My Little Pony: Friendship Is Magic/Minor Characters/WMG

Guesses about minor and background characters. If you have a guess about something else, then

"Meta Guesses go here

Setting Guesses go here

Mane Character Guesses go here

BUT Pinkie Pie Guesses go here

Secondary Character Guesses go here

Royalty Guesses go here

Future Stories go here

Jossed Guesses go here

Confirmed Guesses go here"

"and you can still go back to the Main WMG Page, here"

The Mayor of Don't Do Anything? I don't think so.
She is powerful, just not in a way that's entertaining to watch.

Ponyville is almost as much an Everytown, America as it's a Quirky Town. A small town that has a one-room school, and no visible dedicated village police nor guard (so far), but somehow always has many ponies wandering through it or stopping to watch the latest distraction somepony has set up. We have also seen the ponies have to care directly for nature, so being far from it would create long commutes for a society that seems to lack either internal combustion engines or a surrogate. My guess is that Ponyville was incorporated as a town in the middle of large areas of farmland and wildland (Applejack's orchard and Fluttershy's meadow aren't alone); although they have a bakery, dress shop, and other non-agricultural specialty stores, it's main function is as a central place where they can come in and get supplies, or sell what they have at market without having to go all the way to Trottingham.

In this situation "Mayor" becomes a title that means "elected administrator". Need a permit? Go directly to the Mayor. Need to pay a fee? Go to the Mayor. Need to turn in your census of how many bunnies were born this year? The Mayor. Need to talk to someone about that fine you've been given? Mayor.

She doesn't have a town council she has to work with, and you had better be on her good side and able to state your case intelligently, because she has the ability to say "NO," and if she does you could still wind up going all the way to Trottingham to get her decision overturned.

For all that, she still works in a two-room city hall, and her desk shares one of them with a wall full of filing cabinets and a large safe (the other room contains a meeting table, but sees more use as storage). If she has any help, it's part-time, and she might work only part-time, herself.

She wasn't seen in "Dragonshy" simply because Twilight Sparkle was given orders directly from the top, Princess Celestia herself. In "Winter Wrap Up" she gave a speech about the deadline, but didn't give direction on how to make it, because her job is to apply guidelines, assign fines, shuffle paperwork, and file records; she doesn't really have any direct means to require anypony to do her bidding beyond that role.

The most powerful political figure in Ponyville is a bureaucrat, and although she bows to the Princess as quickly as anypony else, she still "outranks" her favorite student. Just don't expect to ever see an episode explaining that because it's a children's show, and it would be boring as hell to watch twenty minutes of government at work.
 * Twilight may not have been given a title of nobility or any official court position as of yet, which would thus make her junior to the Mayor politically. While Celestia went straight to Twi to deal with the dragon, it may have been a test for her student rather than any official duty.
 * In "A Bird in the Hoof," Princess Celestia excuses herself from the party early, explaining that the Mayor needs to speak with her. If the Mayor didn't do anything and was just a figurehead, it's strange that she wouldn't just go to the party herself and meet the Princess there, instead of requesting a separate audience.
 * In "The Last Roundup" it's explained/confirmed that the large, three-story building at the center of Ponyville (where everypony gathered to greet Princess Celestia in the very first two episodes of Season 1) is actually the Town Hall. Since that is where her office would naturally be located (and it has a basement as well), the part of this guess describing where The Mayor's office is located is way off. However, as this guess is mostly about her role in Ponyville's government, it isn't jossed yet.

The Mayor's real name is Emma Anne Alpha.
Regardless of whether we find out what she does all day or not (see the "Mayor of Don't Do Anything" guess, above), the show's love of meaningful names and pun-based names suggests she will have a name that confirms her status as Ponyville's elected head, so I'm guessing Emma Anne Alpha ("I'm an alpha"). The alpha female in a herd of horses will often be an old mare.
 * Someone wrote a fic where her name was "Mar" pronounced the same way as mare and Mayor... making her the Mayor mare, Mar.
 * Another possible name is Flitter Flutter, She resembles a white haired version of The G3.5 version right down to the cutie mark, apparently she is also the mayor in that version.

The Mayor was dressed as John Wayne Gates-cy.
He killed over thirty stallions and colts and stuffed them into his barn before being caught. Of course, she doesn't explain it to the children.

The Mayor has a clown-phobia.
Would explain why she never seemed to realize trying to be scary in a clown costume wouldn't work. For her, it was the only thing that would.
 * If coulrophobia is anything like arachnophobia, the Mayor would be too freaked out to have even obtained the costume, much less dressed in it.

Mayor Mare is Flitter Flutter.
She seems like one big Shout-Out to her. Eyeglasses, both being the mayor, similar Cutie Marks...

The Mayor was in on the entire Mare-Do-Well scheme from the start.
That is why she recognized and named the new "hero" so quickly, and soon gave her her own day of appreciation as well without arranging one for Rainbow Dash. Twilight and the other ponies approached her with their idea and recruited her assistance to drive the lesson home.

The Mayor is the same age as the mane cast.
She dyes her mane to give the illusion of age, wisdom and respectability, but she went to school with Applejack and Rarity. Her special talent relates to her role as mayor, and her cutie mark was what landed her the job in the first place, even when she was too young to be able to handle it properly. That's why she seems so incompetent in some episodes - she's really inexperienced. The ponies next to her in the background of "Smile" are her parents.

The Mayor is only in her first term in office, and was unprepared for how much trouble Ponyville would be.
She's clearly unprepared for all the weirdness of Ponyville, and even routine stuff, like Winter Wrap Up, still throws her off. Obviously, whoever her predecessor was didn't bother to fill her in.

The Mayor used to be the town librarian.
The post was empty when Twilight arrived, and the Mayor is not the best at organization. In the time between her taking office and Twilight's arrival, she was never able to get around to appointing a new librarian.

Each male (non background) character represents a certain aspect of the brony community.

 * Big Macintosh represents the maturity of the bronies.
 * Pipsqueak represents the bronies' favor of Luna over Celestia.
 * Fancy Pants represents the kindness of the bronies.
 * Snips and Snails represent the Fan Dumb portion of bronydom.
 * The royal guards represents the bronies' devotion to their fandom.

Screwball runs a shop of a similar nature to Quills and Sofas
She sells nothing but screws and baseballs.
 * Or she's a Baseball pitcher, judging by how zany she is when discorded, we can surmise that she takes her role very seriously

The veterinarian is related to Fluttershy.
It's popular fan theory that Fluttershy has earth pony ancestry. The unnamed veterinarian from "Secret of My Excess" just happens to be an earth pony with a yellow coat. Coincidence, or a talent for working with animals running in the family? The two are related in some way, and given what "Baby Cakes" has shown us about pony crossbreeds, it could be any relationship at all, although the nameless vet is obviously older. Is she Fluttershy's aunt? A big sister? Or could she possibly be... Flutter Mom?!

The Town Hall was already in a terrible state of disrepair before Derpy flew into it.
It was only made worse by Derpy, but did anyone notice how Rainbow pushed the nail into the beam without a hammer? That doesn't seem like the kind of wood to use for a building. Perhaps it was infested with termites and it should have been condemned and torn down.

Coconut was never inclined to try acrobatics.
That's why Discord made him walk upside-down and sideways on air.

The Mayor purposely dyes her hair gray because of Pinkie Pie.
Or rather, she doesn't want to be that closely associated with Pinkie and her ilk. She probably thinks that no one would take her seriously if she had a crazy hair color. It is basically her greatest fear. Hence the clown costume on Nightmare Night.
 * Or maybe she's even related to Pinkie Pie, and doesn't want people to know.

Coconut, Big Macintosh, Granny Smith, Screwball, and the three buffalo all have the potential to wield some Element of Harmony.
Therefore, learning from his mistake a thousand years earlier, Discord Mind Raped them preemptively.

Big McLargehooves has a substantial collection of the Smarty Pants line.
Real Stallions Like Smarty Pants, after all.

The Diamond Dogs wanted those gems for reasons other than greed.
They might've wanted to cash in those gems to get something they really needed, like bathtubs or a cleaner home.
 * They may once have been Princess Celestia's royal miners, upstaged by ponies, and they want to show the Princess they can work better than any pony (by using a pony).
 * They might've been gathering those gems for someone else, like a hungry dragon.
 * They might eat gems just like dragons.

The Diamond Dogs will return with their tails between their legs

 * After their run-in with Rarity, the Diamond Dogs are now devoid of gems. Because of this, they have nothing with which to pay their tributes to the Dogfather. They will be begging Rarity and her friends for help.

Gilda will have a Woobie past episode.
Wherein we are shown that she is insanely jealous, antagonizes everypony and everybody, and clings to Rainbow Dash so much because her childhood was a very bad one. Her parents suffered extremely rocky relationship problems, which led to a divorce, which led to a string of new boyfriends, another divorce, numerous schools (and little time to make friends in any of them), till a much-needed break and Crowning Moment of Heartwarming when she gets custody with her "Daddy" (one of her mom's nicer and honestly affectionate boyfriends).

Then yet another painful (if temporary) separation when Gilda has to be sent to Flight Camp.

Flight Camp is even worse, where the drive for competition and not being in the loser bracket drives Gilda to be good simply because she's afraid of being stuck as the odd-one-out again. Their graduation, and Gilda's being presumably geographically separated from one of her only friends in her entire life contributes to her present day personality.

Gilda will return in a later episode.
The moral for said episode will be how anyone has a chance of redemption.

Glida will return and Rainbow Dash will find out how mean she really was to her friends
The episode ended without Rainbow Dash finding out Glida had treated two of her friends, including the shy, timid one who even she knows is too sensitive for a simple prank. Rainbow Dash will find this out and where it goes from there depends if Glida is a villain in that episode or going to be given a shot for redemption. But I can bet Rainbow Dash will be ticked.

Absolutely NONE of the villains in this show will ever repeat.
All villains of this show are one-time-use. They show up, are defeated, and don't come back (not even Nightmare Moon, who in "Luna Eclipsed" was actually Princess Luna with a disguise). Wave good-bye to Discord, Gilda, and the Diamond Dogs because this show is about friendship, not beating bad guys. Expect Diamond Tiara and Silver Spoon to remain, but to lose the bratty, snobbish, superior attitudes.
 * The only villains who make another appearance will be the witches from the volcano of gloom.
 * I hope not, because that'll be a major case of They Wasted a Perfectly Good Character.
 * It's not a joss, but this post over at Equestria Daily gives a clue about Season 2's last three episodes that is interpreted by the some commenters to mean "more from evil characters," which could shoot down this guess. Not enough to go on, but worth watching.

Either Trixie or Gilda will pull a Heel Face Turn.
But they'd be Reformed but Rejected. After proving themselves, the Aesop of the episode would be that some can change, despite their past.

Some of the villains will team up and pull an All Your Base Are Belong to Us on Ponyville.
While the mane cast are away, they take control of the town and prepare a trap for the Elements. It would be a A Day in the Limelight for the secondary characters such as Big Macintosh, the CMC, the Mayor, and so on who have to stop the bad guys.
 * Maybe Derpy, Doctor Whooves, and all the other popular background ponies will join in as well?

We're going to get a Big Damn Villains moment from previous antagonists like Trixie and Gilda
They may be jerks, but I doubt they want to see Discord tear down the walls of reality any more than anyone else.
 * Jossed. Unless Discord makes a return.

Other possible Freudian Excuses for the villains.

 * Gilda's possibly been a victim of Fantastic Racism at Flight Camp with Rainbow Dash being the only one that was nice to her.
 * Trixie's possibly been second rate too many times, thus made her love for attention.
 * Both Diamond Tiara and Silver Spoon's families paid no attention to their respective daughters and was often ignored like Remy from The Fairly Odd Parents.
 * Diamond Tiara's Dad has been shown to be quite kind and he does take care of his daughter. Silverspoon however....
 * As the guy who created this, that's probably when Filthy Rich wasn't busy with work. Her mother on the other hand, we have yet to see...
 * The Flim Flam brothers' probably grew up in poverty and find ways to make money even when it's shady at best.
 * Iron Will was probably the weakest and meekest from where he's from, so he buffed up to take revenge on his tormenters, and made sure no one shared his fate.

The Windigos will arise as recurring villains.
Shortly after Return of Harmony part 2, Jayson mentioned another villain would be introduced in Season 2. The very nature of the Windigo simply scream "next-big threat": powerful, potent Eldritch Abomination, feeding off of hatred and animosity, and. The Windigo race would probably act as a Knight of Cerebus.

The Flim Flam brothers were conjoined twins
It seems from their cutie marks that it looks like the same one, just divided. Maybe twins have a special connection cutie mark wise?

The Flim Flam brothers will hold a grudge against the Apple Clan for 'ruining their livelihood'.
In pure 'Never Our Fault' fashion, they'll blame Applejack and her family for the bad press resulting from their actions during "The Super Speedy Cider Squeezy 6000". Rather than acknowledge their own actions are responsible, they'll paint themselves as the victims.
 * Especially if the Apples decided to warn their absolutely massive family about the two jerks.

Along these same lines...

The Flim Flam brothers will try and ruin the Apple Clan's reputation in another town.
Which Applejack and the others won't know about until they're visiting that area for some reason, leading to a Hero with Bad Publicity plot.

One of the Flim Flam brothers is Trixie's ex-boyfriend.
It ended explosively and they've been on the run for their lives ever since. Part of the reason that they wanted Sweet Apple Acres is so they could turn the place into a veritable anti-Trixie fortress. There's no logic to this, I just think it'd be funny.

The Flim Flam brothers' cutie marks are fake.
Their cutie marks suggest some kind of affinity for growing or cooking with apples, yet the plot suggests that their talents are more about being Gadgeteer Genius Snake Oil Salesponies than anything else. They certainly don't seem to care about the actual art of cidering for its own sake. More likely, they use magic to conceal their true cutie marks (which are probably bottles of snake oil) and cover them with an illusion of a cutie mark appropriate to whatever trade they're trying to ply this time.

The Flim Flam Brothers are screwed
They just made an enemy of the largest family of Apple Farmers in Equestria, who are tight knit. Just how do you think the Apple Clan is going to react to being told about these two jerks who tried to swindle their kin out of house and home?

The Flim Flam Brothers are either related to or members of the Apple family.
If the cutie marks aren't fake, that is. They could be extremely distant relatives, or the black sheep of the family. The reason the other Apple family members didn't recognize them could be that they either never met them or had never known they had MORE family members.

The Flim Flam Brothers and Trixie are siblings.
A pair of unicorns show up with a strange vehicle, touting how incredible and famous they are (yet apparently no one in Ponyville has ever heard of them?), put on a Large Ham -ish performance and earn the adoration of nearly everyone for this...and despite clearly having skill, overtout it and...well, act like jerks for the sake of acting like jerks? Pumpkin and Pound, not to mention the Pie family and even the Apples themselves, show that pony colorations/body types can vary wildly in a family. They're just too similar for it to be a coincidence.

The Super Speedy Cider thingamawhatsit... wasn't always that.
The Flim-Flam brothers simply retrofit it for whatever function the town they visit next will need it the most for. Their cutie marks are probably press-on since they don't have any relevance to their names. And the unicorn magic will plug up any engineering faults left over from the modifications.

And the engineers responsible for those modifications?
The ponies with the hammer and wrench cutie marks, of course. They've been in Ponyville for some time, as MOLES.

The Flim-Flam brothers are psychopaths.
Not Hollywood psychopaths, like Mr. Blonde or Anton Chigurh, the kind you're more likely to come across in real life. Flim and Flam possess a glib and superficial charm that wins the townsfolk over, but underneath those affable exteriors lurk hearts without a shred of empathy and minds without conscience. Look how much delight they take in rubbing their victory in the Apples' faces. The brothers live a parasitic existence, preying on others' hard work and reaping the benefits without any effort themselves, and once they've made good use of their victims, they drop them like hot biscuits and move on to repeat the cycle.
 * So they're twin Ferris Buellers?

The Windigos arent villains
Without the Windegos freezing, the fighting of the 3 tribes would of awakened Discord. But due to their freezing nature the tribes worked together and discovered the Fires Of Friendship

Iron Will and Gilda are the same species
Ponies have Land Air and Magic. Mythologicals have Land and Air.

Iron Will's used to customers trying to bully their way out of not paying.
There's a fine line between confidence and overconfidence, and his clients stray too far into the latter all too often. He wants them to learn how to take on the world, but not to the point of thinking they can get away with anything.

In fact, he may consider this to be the last lesson for his students: know your limits. His willingness to fight Fluttershy wasn't necessarily a bluff -- rather, he was calling her bluff. If need be, he very well could have smacked her around a little, probably while calling her out on getting his lessons all wrong. Her response to this convinced him she wasn't just trying to weasel out of paying, which is why he backed down gracefully.

Iron Will's money back guarantee is a Secret Test of Character.
Iron Will is running a business, sure, but he really does care about helping ponies to be assertive. If anypony can stand up to him when he comes to collect his fee, then he lets them go without paying, because that level of assertiveness is what he really wants to see.

Gilda took Iron Will's courses when she was younger, or at least the same family of self-help lessons.
She wasn't a full-on Fluttershy in terms of getting pushed around, but as the odd one out in Equestria was still frustrated with shoddy treatment. It's just that unlike Fluttershy, she never had a My God, What Have I Done? moment and continued to live life as an overbearing jerk around those she didn't respect.

Snips and Snails will get a puppy dog named Tails.
Just because they need to complete the expression, "What are little boys made of?"
 * And they will meet two fillies named Sugar, Spice, and a kitten named Nice.
 * And then someone will give them superpowers with Chemical X.
 * You made my day.
 * No no no. A pair named Sugar and Spice, unless a pony named Tails shows up.
 * And they will be a Tomboy and Girly Girl pair.
 * "Tails" could be the nickname of another pony, much like how Pinkie is short for "Pinkamena". OR he could be the homonym "Tales" whose special talent is story-telling. He will be Trixie's brother, in fact. Also, I think if Sugar and Spice are Tomboy and Girly Girl, Spice should be the girly girl and Sugar the tomboy as a neat subversion. AND they will be colour-coded like the Powerpuff Girls (Spice will be green, Sugar is pink, and Nice is blue)
 * And then they'll meet three tigers named Dragonflies, Katydids, and Chewed-Up Little Kids.

Snips will be seen cutting somepony's hair before the series ends (but not during Season 2).
Because that's the calling indicated by his cutie mark. He's a natural barber. It will be a background action, and not important to the story itself.
 * I have no idea what Snails' calling happens to be.
 * A Malacologist (Someone who studies snails).
 * Snails will specialize in very slow, deep thoughts (My Little Philosopher?)
 * Like a snail, Snails' special talent seems to be eating plants. He'll probably be a farmer or a market gardener.

== Snips got his cutie mark offscreen during Applejack's game from Adventures in Ponyville. == In the game's intro, Snips has no cutie mark, but in the game itself, his cutie mark is there. Rather than being an animation error, perhaps he discovered his special talent after fleeing from Applejack but before returning for more apples. And it wouldn't be a continuity error, since the game was Snips and Snails' first appearance.

Snips and Snails are brothers
And are cousins of Derpy.

The show will continue to show Snips and Snails as comic relief characters but then...
...suddenly, they'll cast a sympathetic light on the duo that makes people sorry they kept laughing at their expense. Eeyup.

Snails is FtM transsexual and going through puberty.
I noticed that he has what looks like eyelashes, and in some shots he almost appears to have slight breasts, his freckles also seem kind of girlish. The fact that s/he is going through puberty could also explain why s/he has such a long neck and large ears, because the grew first. This would also explain why Snips is so tiny still because girls start puberty on average about two years before boys. His Cutie Mark could reference the fact that s/he is a boy trapped in a girl's body.

Silverspoon is Related to Hoity Toity.
Most likely, She's his daughter. Why is she living in Ponyville instead of Canterlot? Because her parents are divorced. Silverspoon lives with her mom (let's call her "Platinum"), but both of her parents try to win her over with gifts, favors, and the like, and as a result she has become a spoiled brat.

Diamond Tiara comes from a neglectful and/or emotionally abusive family.
She is always wearing a tiara on her head (a freaking tiara, rather than a bow or ribbon or headband), a ploy to get attention. She becomes visibly distressed at the prospect of being upstaged at her own Cutecinera and having people pay more attention to the CMC than herself at said event. She and Silverspoon briefly mention how awful it would be to be "not special," and she is constantly going on about her Cutie Mark in her debut episode. This could mean one of two things: Her family places absurdly high expectations on her and expects her to be supremely special, important, and to stand out above everyone else--which is partly why she wears her tiara. When she fails to meet said expectations, when other ponies are paid attention to over her, her parents berate and punish her. Alternatively, no one in her family pays attention to her, so her talk of being special and her need to be noticed is because of that--she just wants someone to love and pay attention to her.
 * Seemingly Jossed by "Family Appreciation Day." Her father seems like a kind a good pony, who is concerned about her brattiness, which might suggest that he has been overindulgent (not uncommon among wealthy parents), but not abusive. One never knows what goes on behind closed doors, and we haven't seen her mother, but it still seems unlikely.

Silver Spoon's special talent is heroin.
Not only is her name Silver Spoon, but her cutie mark is also a silver spoon, which is a tool used in cooking heroin. Diamond Tiara is her biggest customer and a huge addict, or as they like to call it, a "sugarlump rump." This is also why Silver Spoon and Diamond Tiara hang out all the time and became friends. As to why they constantly act like total brats, they're either high (so they don't care), or going through withdrawal (and highly agitated because of it).
 * You really think they're going to make characters drug addicts in a children's cartoon?
 * Yes.

Diamond Tiara's and Silver Spoon's Special Talents are not being Alpha Bitches.
Diamond Tiara is actually a natural with accessories, particularly jewelry. She may even end up opening a shop in competition, or partnership with Rarity's Carousel Boutique.

Silver Spoon is a great chef, focusing entirely on Upper Crust fine dining. The kind that comes in small portions at high prices, Like we saw in Applejack's flashback in The Cutie Mark Chronicles.

The reason they're both Alpha Bitches anyway is that they think their High-Class Special Talents make them better than everypony else.


 * Alternatively, Diamond Tiara's talent is leadership, since a tiara is a symbol of authority. She's the Alpha Bitch, but she's the kind of Alpha Bitch who actually gets things done at school. If the Ponyville school has clubs and societies, she's president of most of them, rules them with an iron hoof, and makes them succeed.
 * Or perhaps Silver Spoon's talent is taking care of fillies, since, you know, "born with a silver spoon in one's mouth".
 * Perhaps her talent is the ability to manipulate cutlery. While this may not sound impressive, remember, Silver Spoon does not have opposable digits nor telekinesis, suggesting that she's got impressive levels of hoof-eye or mouth-eye coordination.
 * Diamond Tiara will work with Rarity, positioning the jewels on the dresses so that they don't like tacky (which they often do, right now).

Pipsqueak is one year old.
He comments that this is his first Nightmare Night Ever, and Terran Horses are able to walk minutes of birth. It's conceivable that Equestrian Ponies would be able to talk within months of birth.

Pipsqueak is an ancestor of Little Pip.
They both share the name Pip, Pipsqueak has probably moved to Ponyville putting him near Stable 2 and they both have brown manes. Faust has stated that the different ponies can interbreed. It would also explain Little Pip's inability to do anything but telekinetic magic. She's probably got more earth pony in her then unicorn.

Pip is really Celestia in disguise.
Basically, Celestia's plan to keep Luna from flattening Ponyville in a rage.

There's an in-universe reason for Pipsqueak's slipping accent.
He's moved from Trottingham to Ponyville some time ago. Less than a year ago, since it was his first Nightmare Night, but some time ago nonetheless. The accent of that region of Equestria has already started rubbing off on him.
 * Alternatively, we can combine this with the guess above: at some point Pipsqueak got replaced by a disguised Celestia, who either didn't know that he was supposed to speak with a different accent, or did not even bother with it.

Twist is In with the In Crowd now that she has her cutie mark.
She appears on stage next to Diamond Tiara and Silver Spoon in "The Show Stoppers", and is one of the only three ponies shown who didn't win an award. So was she next to them...or with them?

When Pipsqueak grows up, he will become one of Luna's Royal Guards.
Heavily inspired by the Pony POV Series. Pip will keep his belief that Luna is "his favorite princess ever" throughout his life, and eventually, when he grows up, he will decide to spend his life in Luna's service. She will pour her essence into him, and he will become one of her Throne Guards. Maybe he will even gain leathery wings, like the guards that pull her carriage.

When Pipsqueak grows up, he'll move back to Trottingham and become a real pirate.
He'll also be at least as big as Macintosh and keep his name for irony's sake.

Pips will join/has joined the CMC.
He doesn't seem to have a Cutie Mark, and he was hanging out with them while trick-or-treating with some other ponies with no Cutie Mark. Pips might be the first colt to join, and his joining will possibly get a few more ponies in and will have something to do with the Cutie Pox episode. He may be a potential love interest for one or more of the CMC original trio, specifically Apple Bloom or Sweetie Belle.
 * Since it is Hasbro's motto to sell toys, Dinky and another pegasus pony will join.
 * Then since their names match so much, Dinky Doo and Pipsqueak will become love interests for one another.
 * Then when The Movie comes out, it will show them in the future and part of Generation Xerox in that they will be the new wielders of the elements of harmony... HOLY CRAP! SOMEONE GET HASBRO TO DO THIS PLEASE!

Twist and Silver Spoon are cousins or are otherwise somehow related.
They both have pink eyes and poor eyesight/at least like to wear glasses. Hell, maybe they're even sisters.

Silver Spoon has a Freudian Excuse/Start of Darkness for her mistreatment of "blank flanks" in her brother.
She has an older brother who is a unicorn. Unfortunately, he was born with a mental and magical disability. Dedicated therapy unlocked his magical ability at an early age… unfortunately his power was never able to escape from his horn, limiting him to transforming how own horn (perhaps initially painfully). Due to his somewhat limited abilities, he got near enough to "capping out" that he got his cutie-mark at a VERY young age when he transformed his horn into a spoon shape to feed her shortly after she was weened. Her cruelty towards blank-flanks is partially backlash against others who explained to her why it was actually a SAD thing that her brother had his mark. Perhaps he was even bullied on the subject. In any case, the nickname "Spoonicorn" was either a term of endearment by his family, or of mockery by other children.
 * If you call this a Freudian Excuse then this this could easily follow the subversion of "Just a psychological How We Got Here", rather than being intended to evoke sympathy. Deconstruction also is likely.

The bellhop pony in "Sweet and Elite" and Snails are related.
Possibly a dad or uncle or something. Because honestly, am I the only one who sees a ton of "family resemblance"?
 * With the acne, I'd say a brother or cousin.

The bellhop pony in "Sweet and Elite" is the pony version of Spirou.
Aside the similarity to Snails mentioned above, his hairstyle and color are somewhat similar to that of Spirou.

Twist is the daughter of the flower trio.
Well, she was seen in a shop that Lily and Daisy were seen running in when Zecora came back into town with the curse mane six. Said shop is implied to be her home. However, Lily and Daisy are her adoptive mothers, while Roseluck is her birth mother(they do share a similar color scheme).

Snips is not really a pony, but a pig wearing a fake horn and trying to fit in with the ponies.
It's pretty obvious when you look at him.

Pipsqueak's Nightmare Fetishist is a psychological defense he's developed...
Against his everyday fear that a hard impact could kill him in a violent explosion. After all, he IS a Pinto.

Pipsqueak will spend his foalhood getting physically and mentally prepped for Luna's Royal Guards.
His exploits will be the stuff of legend, and his death will be one badass Heroic Sacrifice.

Snails will grow up to be their universes version of Gil Grissom.
His bug cutie mark is fortelling an encyclopedic knowledge of bugs that he will then use to solve crimes in Equestria's version of Las Vegas.

Pipsqueak's special talent will be taking care of foals.
Meaningful nomenclature. That's really the only reason I can think of.

Diamond Tiara's a colt.
Her special talent is being a Drag Queen. She's even convinced herself.
 * And exactly how do you dress in drag when you don't wear clothes?
 * "she" constantly wearing a tiara, doesn't "she". Diamond just happened to be a more subtle one.

Featherweight got the position of Head Editor by blackmailing Cheerilee.
And he still has blackmail photographs on most of Ponyville's residents.

Featherweight got the position of Head Editor by showing Cheerilee the photo of Diamond Tiara blackmailing the CMC.
You can see him taking a picture in that scene.

Featherweight is this universe's "Spider-Man".
Let's see now, he's Adorkable, a photographer, has brown hair, and is lightweight (as his name and cutie mark suggest) and a pegasus which means he's probably very agile. (Spiderman is known for being one of the more agile superheroes.) Although he probably goes by Spidercolt.

Pipsqueak's second Nightmare Night, he goes as a diamond dog.
Thus going from pirate to C-dog.

The reason the Cutiemark Crusaders don't have their marks yet is because they're trying too many things at once.
All of them already have traits that would give them their marks if they would just focus on what they already like to do, all they need to do to get their marks is to not be impatient.

There will be a Spoof Aesop where Silver Spoon and Diamond Tiara learn not to look down on the CMC for not having their marks yet.
They will instead learn to look down on them for all the devastation they have wrought in their wake on their quest to find their marks.

Spitfire is Scootaloo's sister.
Unlikely. Scoot might be a bit thick sometimes, but if Spitfire, a Wonderbolt, were her sister she'd have bragged about this to Rainbow at the FIRST opportunity. There's no way that Scootaloo, being such a huge fan of Rainbow, wouldn't have learned that Rainbow herself is a fan of the Wonderbolts.
 * Perhaps Spitfire has a Secret Identity?
 * Spitfire IS the secret identity, ie. a stage name. Her real name?

Spitfire's & Soarin's cutie marks have nothing to do with flying.
We haven't seen any Wonderbolts out of costume and there's nothing to suggest that a pony's special talent has to be flying in order to get into the Wonderbolts. It would also provide some comedic irony when Rainbow Dash finds out that her idols special talent is something completely unreleated like sewing or fishing or something. Some guesses...
 * Soarin's cutie mark is a chef's hat or something related to cooking. He clearly loves homemade pies, what if he was a chef before joining the Wonderbolts?
 * Their cutie marks are on their costumes.
 * No they don't. Those are some kind of insignia/symbol other than a cutie mark, unless you think that nearly every Wonderbolt has one of two cutie marks.
 * Well, cutie marks do repeat, but only two cutie marks for all the Wonderbolts would be a bit odd.
 * It is possible, but it's unlikely. Just about every pony we've seen has made their cutie mark talent into their career. Still, it would be interesting if it's true.

Soarin' is one of the founders of the Wonderbolts.
His cutie mark is the Wonderbolts logo.

Soarin' is a major Ascended Fanboy
Again, his cutie mark is the Wonderbolts logo. It's kind of hard to interpret that as something other than "Grow up to become a Wonderbolt."

One of the Wonderbolts is Surprise from G1.
She has a yellow mane, and white fur like Surprise. They're both Pegasi, and it would go great with the "S" theme (Soarin', Spitfire..) "Rainbow Dash: Pinkie! Why didn't you tell me your Aunt Surprise was a Wonderbolt?!
 * It would be hilarious if it turned out she was related to Pinkie Pie somehow…

Pinkie Pie: Cause then it wouldn't be a SURPRISE! Silly pony!"

"Pinkie Pie: You never asked."
 * Alternatively:

Photo Finish is actually Rainbow Dash in disguise.
As shown here.
 * This theory explains everything! G4 Rainbow Dash is in fact G3 Rainbow Dash after gaining wings from a spell (if Rarity could get magic wings, why not Rainbow Dash?). Since then, she's been trying to get past her reputation as a 'girly girl' pony, so she secretly developed her Photo Finish persona to continue her fashion-related hobbies in secret.
 * So does this mean that Real Tomboys Wear Pink?

== Just like the Blue Angels are drawn from US Naval, Air Force, and Marine Corps personnel, the members of the Wonderbolts are all specially-selected members of the Equestria Armed Forces ==
 * In what reality? The Blue Angels are picked from Department of the Navy personnel (i.e. the Navy and Marine Corps.) The Air Force has their own stunt team. However, with the overall idea that they're an elite unit, that I can buy.

The Wonderbolts came from humble origins before earning their fame.
Soarin' wasn't above Applejack's "commoner food" because he was a commoner once.
 * It's pretty likely. Being a Wonderbolt isn't about being born into fame or wealth, it's about being a talented flier with a passion for the job. Also, only Blueblood, out of ALL the ponies at the Gala, expressed strong distaste for "commoner food", and that's because he's an enormous snob. Being born into wealth doesn't necessarily mean a pony will only eat fancy food.
 * The rest of the ponies there were deliberately ignoring the cart. And when one "accidentally" tripped and Applejack helped him up before offering, he turned a haughty nose on her.
 * I don't know. Being charged for fairly simple fair when there is a catered upscale banquet not 50 feet away seems tacky. Soarin' probably just really likes pie.

Everyone's guesses about Twilight's Starswirl the Bearded costume were right.
Starswirl played country music as a hobby, performed clown tricks on the street to pay for magic college, and now resides at the old folk's home. He's pretty cranky because nopony recognizes him.
 * Considering Luna recognized him, he must be one elderly stallion if he's still at that old folk's home.
 * Twilight told Spike that Starswirl created over 200 different spells; one of them could easily have been longevity. He just forgot the eternal youth part.

The song "You're So Vain" by Carly Simons is actually about Prince Blueblood.
It seems to fit mostly... At least from Rarity's perspective.

Prince Blueblood will return in Season 2 as a Stalker with a Crush/Ladykiller in Love
Blueblood seems like the kind of guy who's used to having the mares fawn over him and do him favors. Rarity seemed like just another fangirl for him to exploit, but she proved to be as stubborn and willful as he. After she told Blueblood off and ran away, he'll probably become obsessed with the one woman he wasn't able to keep wrapped around his hoof and try to woo her (unsuccessfully).

Prince Blueblood's title doesn't come from his distant relationship with Celestia and Luna.
It comes from a much closer relationship with one of the G1 Princess Ponies.

Blueblood is not actually such a jerk.
He would constantly be fawned over by girls like Rarity looking for their dream stallion. He knew that they didn't like him for his personality or anything about him other than his good looks or the idea of the perfect prince. His solution is to show no redeemable qualities so the girls stop hounding him. Even the smallest nice gesture would feed into their fantasies.
 * Interesting theory, but, if correct, then his strategy is completely counterproductive. It ensures that he will drive away only those mares who actually do care about his character, and would love him for his goodness and decency. By contrast, those mares who only care that he's a wealthy prince would continue to pursue him despite his apparently poor character.
 * Not necessarily. Even giving Blueblood a little too much credit, it could be a Secret Test of Character: If the girl doesn't complain and does everything he asks, she's an extreme doormat and not worth of his time. If she just storms off, then she's a bitch that, while won't let anyone take advantage of her, she also won't say what's bothering her. When someone calls him out, bingo, perfect mate. Of course Rarity and the others had to run away before he could say anything else, and Rarity called him out a little too much.
 * At that point, anyone that manipulative is precisely such a jerk. Since when are patience and forbearance character flaws? For that matter, why shouldn't any of his dates just storm off? It's not their responsibility to point out and explain his character flaws, which are obvious anyway. If you are correct, his belief that he has the right to treat his dates in such a manipulative manner is precisely what makes him such a self-centered, selfish jerk.
 * Oh yeah... regardless of his motives for acting like a jerk, he is... well, a jerk. Even if he is trying to weed out the good from the bad, his real character showed in the moment of panic, when he used Rarity as a shield.

Prince Blueblood is not actually a prince.
Prince just happens to be his first name, like Prince. He's just so full of himself that he acts like he's royalty just because his name is Prince Blueblood!

Prince Blueblood is actually a duke.
He's just called a prince. His situation is analogous to that of "Prince" William and "Princess" Catherine: their actual titles are the Duke and Duchess of Cambridge, but they are called Prince and Princess anyway, mostly just as a shorthand.
 * Come to think of it I seem to recall Lauren Faust stating that she wanted Blueblood's title to be "Duke" but apparently eight-year-old girls don't know what that means. Similar to the situation with Celestia.
 * Which was good, because apparently some adult fans didn't know what a duke was either.
 * Perhaps, but really, unless you sit down and study that sort of thing on your own, you're not likely to know what what any of it means in all its details; however, you still get the point that it's a title of some importance without being a prince or king. And if, later, you do want to know what it means, it's trivial to look up in the Information Age.

Prince Blueblood's cutie mark isn't just an eight pointed star, it's a compass rose.
It fits the shape perfectly, and navigation has been a royal skill in the past, e.g. Prince Henry the Navigator, from Portugal.

Blueblood will pull a Face Heel Turn.
He will become either The Starscream, The Mole, or The Quisling.
 * Blueblood as The Quisling would be awesome, and surprisingly fitting. He might side with the antagonists as a misguided attempt at some revenge toward Rarity (or even his great-great-great etc. aunt, Princess Celestia)

Prince Blueblood is fighting for gender equality
Think about what gets labeled him as a jerk: expecting his companion to hold open the door for him, make sure he doesn't step in any puddles, and pay for his food. If Rarity or any other mare went in with the same expectations, she wouldn't get called out on it. Even if a mare ended up using him as a pony shield, it would be considered funny rather than a sign of character deficiency. Clearly, Blueblood is just out to expose a double standard.
 * Though he's being a bit of a jerkass about it if that's the case- common courtesy and chivalry aren't the same thing, and insulting Applejack gained him nothing.

Hoity Toity and Spike are friends.
Hoity Toity watched Rarity's fashion shows as a favor to Spike.

We will see the Wonderbolts without their flying suits.
Or at the very least, Spitfire and Soarin'.

Fancy Pants has a similar background to Rarity.
From what we've seen of most Canterlot High Society, anything that isn't ridiculously luxurious or hoity toity is either seen as sub-human (equine?) and a waste of space, or the ponies are incapable of an original or independent thought. However, Fancy Pants is the only pony to not only tolerate something 'country,' but actually approve of it.

It is quite possible that, like Rarity, Fancy Pants was born and raised in some backwater town in the country, but had an eye for fashion coupled with a similarly generous heart, the latter of which may have been buried by the need to fit into High Society. Seeing Rarity and her friends, he saw something of his younger self, and decided to stand up for her, since no pony did that when he was starting out.
 * I’m not sure how things work in America, but in England we have country gentry (posh people). They generally live on a manor in the middle of a field, own lots of farmland, and the smart ones will generally be very knowledgeable and respectful of the work that comes from living off the land. Due to their distance from others of the same crust they will often count many friends among the common folk as well. Fancy Pants's tolerance may well come from being from one of those families. Teddy Roosevelt (who many people compared him to) is quite a good example.

That mare with Fancy Pants? Trophy Wife.
The buck is probably rich as sin and among the highest of society. That mare has the look of some sort of supermodel with legs that go on and on and on. It has the look of a perfect superficial relationship. Hoc, ergo hoc. Of course, this being My Little Pony, that doesn't mean that there isn't some genuine affection between them. It's just a tinsy bit more shallow than usual.

Fancy Pants is less nice than he appears.
In reality he's a social Chessmaster surrounded by rank amateurs. His influence relies on everyone else making sure he's right about everything and loving every minute of it. Throughout the episode he helped buoy Rarity's reputation and rescue her from embarrassment -- and why shouldn't he? He's already nailed his colors to her mast. If she looks bad at this point, he looks fallible. And at the end of the episode he was probably the only one to recognize Twilight Sparkle - the personal student of Celestia. So what he had there was an apparently close group of friends at least two of whom knew the Princess personally. Now what's the best action for keeping up his own appearances here -- allowing his guests to mock them and risking the Princess's displeasure should she ever find out about it, or trusting that his guests will go along with whatever he says and using that fact to further indebt Rarity to himself?

That's not Fancy Pants's wife, that's his bodyguard.
Fancy Pants is important enough to need a bodyguard. How better to hide concealed muscle than in somepony who looks like a wife or mistress? She looks delicate but is lightning quick and skilled at martial arts, and knows enough magic tricks to incapacitate a foe at a distance. Look at the way she dashed off after Fancy Pants when he left the conversation - that wasn't "my husband / meal ticket is straying", that was "my principal needs me to cover him". Bonus points if she actually introduces herself by the name "Trophy Wife" as a cover.

The mare hanging around Fancy Pants was actually a con artist.
Which explains her lack of definite name (Fleur-de-Lis, Prize Gem, Elizabeth, etc.); they're all aliases. She's hanging around Fancy Pants because she wants his money, and to get that she needs to earn his trust. Also, she was considering conning Rarity, hence her line of dialogue ("A pony with expensive tastes, I see").

Fleur suffers from "You're Smarter Than You Look" syndrome.
She is, in actuality, a very good historian and records keeper, but most ponies look at her and see legs. And that's it. She married Fancy Pants because he not only saw past that, but funded some of her digs; in fact, she was the one who ran a background check on Rarity (and the reason Fancy Pants pretended to go along with whatever Rarity said, even though he probably knew she was lying).

Fleur is the sister/cousin of Fancypants and has a Big Sister Instinct towards him.
If Fancypants is as wealthy as he appears, his parents may have asked their niece/their daughter to look after her cousin/little brother. That could involve Fleur doing a background check on Rarity like in the previous WMG for slight different reasons.

Fancypants is a Troll.
Fancypants knew all along that Rarity was a small-town mare, but quite liked her anyway, and he wanted to have some fun at the expense of Canterlot's annoying gentry and peerage, especially Jet Set and Upper Crust and their ilk. By elevating somepony less polished into the heights of Canterlot society, and giving her his full support, he forces the rest of society to bend over backwards to accept her, which he finds very amusing. It also gets Rarity the connections she always wanted, which makes her happy and thus makes him happy.

Equestrian aristocrats have astronomy-related cutie marks.
At least the high-ranking ones do. If you look closely at the guests at the Grand Galloping Gala in "Best Night Ever", a lot of them have astronomy-related cutie marks. Prince Blueblood has an eight-pointed, stylized star; the guest who stumbles over Applejack's apples during the "Pony Pokey" has a reflector telescope mark; a pony who shakes Twilight's hoof too vigorously during the same song has the constellation Orion; a blue pony with a black, slicked back mane who is standing to the left when Pinkie squeals "the shiny dance floor!" who has three five-pointed stars; and, just after Applejack sings "and I'll a lot of money/ for the Apple family" during the "At the Gala" song, there is a group of six unicorns, including two identical brown ones who both have stylized suns, a dark blue one and a white one both with two small stars and a large one, and another dark blue one and a grey one with an eight-pointed stars like Blueblood's. (Most of those ponies were visible in multiple scenes at the party, not just at the points I mentioned.) And when you think about it, this makes sense: the goddess-princesses who rule Equestria are associated with the sun and moon, and have corresponding cutie marks, so it's not surprising that the aristocracy, perhaps as a sign of their relationship to the sovereign, also have astronomy-related marks. This might also connect to the guess above that Twilight is related to the princesses: her cutie mark is also a star pattern, as is her mother's (a different star pattern), while her father's is two crescent moons. At the very least, it implies that the Sparkle family is of noble blood.
 * That the Sparkle family are important aristocrats received powerful support in "A Canterlot Wedding": first, Twilight's governess when she was a foal was a royal princess, and second, her elder brother is considered a suitable husband for said princess.

Prince Blueblood is actually a Troll.
He's somewhat of a jerk, but only in the sense that he likes trolling. He realized he had went top far with Rarity after she yelled at him, but he was a little freaked out by her anger. The reason why he's so close to Rarity in Sweet and Elite? When he found out that Rarity was in Canterlot, he tracked her down to apologize.
 * Plus, he's related to Celestia.
 * My theory is that he has met countless mares who have Rarity's fantasy and sick of being treated like some prize to be won, proceeds to mess with them by throwing their expectations back in their face. Without Rarity acting like some (in his eyes) gold digging w-horse, he doesn't act like a jackass to her, and shares something he may actually like, like blimps.

An improved Prince Blueblood will feature in a future episode.
The lesson, learned by Rarity, will be that ponies change and forgiveness is a good thing.

Prince Blueblood's title comes not from any relationship to Princess Celestia, but rather to descent from Princess Platinum.
We know from "Hearth's Warming Eve" that the unicorns had a monarchy before Celestia and Luna rose to political power. Perhaps that royal family kept its titles even after Celestia took over.
 * Expanding on this, he's actually the descendant of the sibling of a consort Princess Celestia/Luna once took, making him more like their (numerous generations removed) nephew-in-law rather than whatever explanation we once got that makes him genetically related.

Prince Blueblood acts the way he does because of the environment he lives in
Most likely, Blueblood is the scion of a royal family that was deposed quite some time ago. Therefore, he has to live up to the stigma of being a prince without a throne to look forward to. Not to mention, the media's eyes are on him, his parents are pressuring him to succeed, he's being constantly harassed by shallow fillies, he's being held to an abnormally high standard... poor guy

Prince Blueblood is gay
How has this not been mentioned yet????
 * So he was only hoping Rarity would be his beard. I approve of this theory.

Fancy Pants is, in fact, of a wealthy family.
Unlike some of the other upper class ponies we see in Sweet and Élite he's chosen, over the course of his life, to be a very nice guy. Free will and all that.

Fleur is Cadence's daughter

 * Given Cadence's approximate age, the opposite is more likely to be true. Which is a good theory in and of itself.

Twilight's parents are the type to get into "my honor student can beat up your honor student" fights.
It's not that they don't love and support Twilight. It's just that when your daughter is apprenticed to the local equivalent of God, it's hard not to brag. "Mommy, why is Daddy telling the neighbors to 'suck it'?" "For great justice, Twilight. For great justice."
 * That's assuming they're not still in therapy from being turned into potted plants.
 * Their daughter just became the apprentice to the world's resident Living God; I imagine Celestia could've easily settled any trauma they might have had, perhaps with an amnesia spell.
 * Given how excited they seemed when Celestia apprenticed Twilight, this WMG is most likely true.

Twilight Sparkle's mother is the original Twilight.
Evidence the pink-to-white color change might be explained a bit as due aging or simply drawing style differences, that also might explain Twilight (Sparkle)'s teleportation abilties(when she explicitly mentioned she didn't know she could do that), she inherited them from her mother and didn't showed up until Nightmare Moon's incident (due being under pressure it activated instinctively, or well due being close to the Elements of Harmony it gave Twilight(Sparkle) a magic boost that allowed her to use that ability which normally would have required her being older in order to cast it)
 * Extremely likely, since Word of God said she intended to have Twilight Sparkle's mom be the original Twilight (though she can't remember if she told that to the people working on the episode).

Twilight's parents work a lot and have neglected their daughter.
They work as much as they can to provide the very best for Twilight, but in the process neglected her. They do care about her, though, which is why they not only applied for her to be at a prestigious school, but made time to go to her entrance exam. This is why Twilight views the Princess so much as a parental figure when every other pony views her as royal authority figure. This also explains why she ignored fun things to study, with the way her parents were, she grew up believing that work was more important than other things, including friendship.

Twilight's mom is named "Twilight" too.
She's Twilight from G1. I'm guessing her maiden name might be "Twilight Twinkle", as a Mythology Gag to the concept art.
 * Wait, does that mean her married name is also Twilight Sparkle? Is her daughter technically Twilight Sparkle, Jr.?
 * Or Twilight the Second. Maybe the name "Twilight" runs in the family?
 * As mentioned above, Faust originally wanted to make Twi a revamped G1 Twilight. When that couldn't happen, she hinted that G1 Twilight is Twi's mother. But for copyright reasons, it's widely believed that the mother is named Twilight Velvet.

Twilight's dad is German.
He seems to be a reference to a German G1 pony named "Nightlight". So why not?
 * Well, the "spa ponies" were based off of English toys and have English accents.
 * Is he from Stutegart? Or maybe Frankfurt-am-Mähne?

Twilight's Parents are Retired Badasses.
Twilight and Shining Armor are the two most powerful unicorns seen yet, and both of them have high positions in Equestrian society. Maybe it runs in the family?

Twilight's family is a military family, and Twilight is the exception.
One of the things Shining Armor was wearing for his wedding outfit belonged to his uncle, and it all looked like military garb. Maybe Twilight's family has a long tradition of joining the Canterlot guard, and Twilight's ambition to become a scholar and magician is an unusual thing for her family (although they fully supported her anyway).

Fluttershy has an Overprotective Dad.
Once we meet Fluttershy's parents, we find out that her father was a former captain of The Wonderbolts. He'll be huge by Pegasus standards and he still thinks of his daughter as the little foal she once was. He'll probably become a bit paranoid about who she has as friends and in turn, they'll be intimidated by him. However, after the course of the episode, he'll learn that she's a big pony and is able to take care of herself and relax.

Rainbow Dash and the unicorn from Robot Unicorn Attack are related in some way.
Either Rainbow Dash is the daughter of the unicorn (Firefly is the mother?), or the unicorn is Rainbow Dash turned cyborg after a horrible crash.
 * Or a night of heavy partying.
 * Given the unicorn's mane coloration, more adult build and horn, it's more likely that the robot unicorn is related to Celestia. (Now I'm getting plot bunnies about it being her king/prince/whatever after a near-death experience, rebuilt using unknown-to-Equestria technology, trying to return to her side.)
 * So, more Steve Austin or Anakin Skywalker, you think?
 * The Robot Unicorn was a scientist in Cloudsdale trying to create the legendary "Double Rainbow" but could not get the desired effect through traditiona; methods so he began ingesting the pure rainbow liquid so he could create the double rainbow himself. Overexposure caused a genetic mutation that was passed to his daughter Rainbow Dash, explaining why she has the unique ability to leave that trail of rainbow in her wake. While Dash turned out stronger from the experience before, her father became a twisted pile of pony wreckage. In an attempt to save his life, he was encased in magic armor. Unfortunately the experience drove him mad he ran away into the wilds of Equestria. Rainbow was too young too remember this. He will then return to wreak havoc on those who's lives he once sought brighten. Leading to this confrontation
 * So RU is a member of the science team that created Power Rangers SPD?

"RU: Celestia never told you about your father!

RD: She told me enough! She told me YOU KILLED HIM!

RU: NO, Rainbow Dash, I AM YOUR FATHER!

RD: NOOOOOOOOOO!!!!!!!!! (alt: OhMYGoshOhMYGoshOhMYGoshOhMYGoshOhMYGoshOhMYGoshOhMYGosh)"

Rainbow Dash's mother runs a seasoning company.
After all, we know that rainbows are spicy.

Applejack's parents are deceased.
This is on the tragic side, true, but it would explain why Granny Smith is staying with three grandchildren. They're her closest remaining kin. (Assuming that Applejack's aunt Brown Betty is Smith's child-in-law's sister, rather than her daughter.)
 * Considering that Applejack warns Apple Bloom that she'll "tell Big Macintosh" on her in "Bridle Gossip", and that when Applejack is leaving home in "Cutie Mark Chronicles", only Big Mac and Granny Smith are there to see her off (and welcome her home), I think this is a fairly safe assumption; the Apple parents are, at least, out of the picture.
 * Except for the fact that Apple Bloom wasn't born when Applejack left for Manehattan. It still may be true, however.
 * We don't actually know that Apple Bloom wasn't born yet, though. For starters, because all the girls' ages are pretty fuzzy, we don't know what the age gap between the two is, nor do we know just how long ago it was that Applejack's story took place. Consequently, Apple Bloom may have been alive at that point in time but so young as to not remember the events nor see Applejack off when she left.
 * Or, maybe Applejack's mother died GIVING BIRTH to Apple Bloom, and their father (in grief) decided to abandon his family and just ran away.
 * In "the Cutie Pox" There's a picture which mimics American Gothic. it features a pink pony and a blue pony. Perhaps these are the mysterious Apple parents.

Applejack is the daughter of G1 Applejack.
It's not a stretch. In G1 Applejack had a daughter, called "Baby Applejack". In G1 there were a bunch of fillies that came out of a magical mirror, and were essentially younger versions of the original Pony. It's not unknown for parents to name their kids after themselves. If they look too similar, than they could just tweak her coloring.
 * ..Is her dad Tex, or does the Mirror exist?

Applejack's parents are not dead, but traveling.
They're traveling the world, promoting the wonders of apples and apple products at all the different fairs, carnivals and festivals around Equestria and beyond.

Applejack's parents are alive and well, but they live in the city.
Because they're the heads of the Apple family farming franchise. Applejack mentions that the rest of her family went home to tend to their own farms after the Summer Sun Celebration, which is why they couldn't help her with the harvest; they were busy with their own. Applejack's parents live out in the city, where the corporate headquarters are, possibly all the way across Equestria, which is why they never even come to visit. They sent their underage daughter to live with her grandmother and siblings in Ponyville to help preserve the company's down-home, independent farmer image.

Applejack's parents are deadbeats.
They're both wildly irresponsible and immature. They're separated and they run from town to town, making them difficult to track. The father walked out on them early and when the mother had custody of the children, they would often be left home unattended with no food or warmth. Granny Smith just couldn't get the parents to change so she convinced them to let her take care of the kids and have them stay at Sweet Apple Acres. Granny Smith does try to get in touch with the parents from time to time, but since they're separated and running all over Equestria, they're just too hard to track, so she focuses on raising the kids right and running the farm. Granny Smith didn't even negotiate with the parents to have Apple Bloom, she was pretty much just dropped off at the farm by her mother and she may or may not have the same father as Applejack and Big Macintosh.

Applejack and her siblings have a bad relationship with their parents.
Their parents have treated them in ways that just caused their relationship to be strained. Maybe they left their children and rarely visit.

Applejack's mother is named "Sweet Apple-Acres".
Her maiden name is "Acres", but her husband's surname is "Apple", hence "the Apple Family". However, for personal reasons she stuck with her maiden name (like Lauren Faust) but kept the "Apple" name as her middle name. After she died, the farm was named after her in her honor.

Rarity's father is an Earth Pony.
We never see him without his hat, and a football cutie mark just doesn't seem fitting for a unicorn.
 * We've seen a football-themed cutie mark on pegasi, and they don't seem that fitting either (I imagine that playing football on clouds is difficult to do). I don't think talents are that closely dependent on what breed of pony you are. So I don't see why an athletic and physically strong unicorn is so strange in this universe at least.

Rarity's father is Ponyville's version of Al Bundy.
He had a promising career in school as a Hoofball player, but ended up as a women's farrier. This fits with his cutie mark and his wife's Peg-like mane-do, and means that Rarity grew up around fashion accessories since her father made and fitted horseshoes. But since this show is far less cynical than Married With Children was, he's actually quite contented with how his life turned out and enjoys helping fillies and mares find proper hoofwear, not to mention that shoeing horses is a fairly butch manual skill, with fire, and iron, and nails. Not like selling cheap high heels to ugly women.

If Pinkie was adopted, her biological mom is Surprise.
Maybe she was abandoned due to being an Earth Pony, or something. Either way, both are Genki Fillies who love pranking people, both have balloon-related Cutie Marks, and annoy the heck out of their friends? It's In the Blood.

Pinkie Pie's parents were killed by parasprites.
How does Pinkie Pie immediately recognise a parasprite in "Swarm of the Century" and how did she know that they were attracted to that particular song? In the Cutie Mark Chronicles, the music that she played at her first party was the same that she used to lure the parasprites, which brought them to her parent's rock farm. There, they destroyed their livelyhood as well as her parents (forcing her to move to Ponyville), while her sisters fled elsewhere.

This is further supported by Word of God that Mr. and Mrs. Cake treat her 'like their daughter', even giving her a place to live and a job (unrealistically kind, even for ponies).

Pinkie Pie's biological father is the Madgod Sheogorath.
Once, Sheogorath left the Shivering Isles to take a long holiday in Equestria. There, he took on the form of a unicorn, and eventually met an earth pony who ended up becoming his best friend. Before he left Equestria, Sheogorath bestowed a gift on his friend--one of the children she would come to bear would be descended from Sheogorath. Later on, this pony would meet and marry a rock farmer, and they would have three children. The pony knew which child was Sheogorath's because it looked different from the other two. Instead of sharing the color scheme of the other two, this child was colored a bright pink. This also explains Pinkie Pie's inherent otherworldly powers and questionable mental state.

Pinkie Pie's parents are miners.
Maybe "rock farm" is just a weird way of saying "coal mine".

Pinkie Pie's parents really are rock farmers.
Someone mentioned in an earlier WMG that gems in Equestria seem to grow like fungus or plants, due to their common presence. If that's the case, could certain rocks be the equivalent of apple trees? Of course, this would then make the Pie Rock Farm an orchard, per se. We already know that dragons eat gems, so maybe they specialize in dragon food and non-culinary crops (after all, apples can be used for more than just food.)

Star Swirl the Bearded’s Amniomorphic Spell…….
…allows a foal fetus to be carried by a male pony, with its base being an amniotic sack formed with magic. There had long been spells allowing two ponies of any gender to mix DNA and conceive a foal together, but before Star Swirl’s breakthrough, the foals would still need to be carried to term by a mare.

This complication discouraged some would-be M/M parents from attempting to have biological foals, and had led to an increasing female percent of the population as F/F parents and their fillies became more frequent.

Because of its rather specific possibly controversial nature, this spell and the mage who literally fathered it remains obscure to most lay ponies, though it is still well known and often used in the medical world.

Star Swirl the Bearded will appear.
Either in an episode that takes place in the past or in a Time Travel episode.

The characters from the Hearth's Warming Eve play were not actually very much like they were in the play
There is a lot of improvisation, ad-libbing, and modifying of roles to fit the actors in a traditional Hearth's Warming Eve play, as hinted by Spike's hamming up the narration to the point of irritating the audience. The mane cast's improv, ad-libbing, and modifications naturally made the characters more like themselves, whereas historically they may have actually been fairly different. Most likely, the overall message of the play is seen as more important than historical lessons, so nobody really cares much how accurate it is.

The characters in the play were all Composite Characters.
It seems most likely that the Hearth's Warming Eve Pageant was an abridged and simplified version of real events. Plus Equestria being founded by 6 mares wouldn't obviously work. It seems more likely that each character was a composite of various figures in Equestrian history: Commander Hurricane represented the Pegasi military, Princess Platinum was supposed to be the Unicorn aristocracy, Chancellor Pudding Head was the Earth Pony goverment. Their advisors were supposed to represent the various layponies and possibly their clergy, scholar, peasant and artisan classes. It's also possible that the characters' personalities were also molded to fit the actors playing them.

Every generation, a few Earth Ponies become Cloudcuckoolanders. Chancellor Puddinghead was one.
It is possible that in each generation of Earth Ponies, a few will become cloudcuckoolanders when they obtain their Cutie Marks. It is from this pool that the Earth Ponies elected their Chancellor, as their off-the-wall advice might be useful at times (this is presuming that the Chancellor was not the ultimate ruler of the Earth Ponies, but an adviser of sorts). Chancellor Puddinghead was one of these ponies. So is Pinkie Pie.

Each of the main characters in the play are direct ancestors to each of the mane cast.
That's why Celestia chose them to play those characters: Generation Xerox is in effect, so only the mane cast would be able to play their ancestors to the best of their abilities.
 * According to Trollestia all of Equestria is descended from those six.

The reason why Princess Platinum rules...
...is because her father, the king, died in the blizzard. Naturally, they couldn't just say that, what with there being young fillies and colts watching in the audience, after all. As for why she's not Queen Platinum: Platinum is basically Rarity turned Up to Eleven. Going by "Princess" because it's prettier or cuter sounds a lot like something Rarity would do, right?
 * Who says she ruled as a princess? She was the representative who was negotiating on behalf of her people, and part of the scout team who discovered Equestria.

Private Pansy...
Was a Badass magnificent Blood Knight with Nerves of Steel and Brass Balls.

And Fluttershy was just a bad actor.

: Private Pansy was just a Punny Name made up for the play
His/Her real name was Private Panzer, and probably was a Mighty Glacier Gentle Giant Martial Pacifist Reluctant Warrior blue Poni counterpart to the Lightning Brusier Hot-Blooded Colonel Kilgore Blood Knight red poni, and because Defeat Means Friendshipor at least summission or some I Owe You My Life incident s/he ended up being Huricane's Dragon against his/her will, wichi may explain why s/he "really, really, really, really, really, really, really, really, really, really dislike(s) her. "

Owlowiscious is aware of the 4th wall.
At the end of the episode, we see him wink at the audience. He doesn't have any of Pinkie's powers though.

Gummy is actually a secret agent.
Gummy may seem like a simple alligator who doesn't do much right? WRONG. He just as to don a Nice Hat and he suddenly jumps a few anthromorphic levels, but he tends to disappear and then reappear at random intervals. This explains why he isn't usually seen with Pinkie. Where does he go and what does he do? Nopony knows.
 * Doobie-doobie doo-wa Agent G!
 * Also, he has an alliterative name (Gummy the Gator), my guess is he works with some Equestrian branch of OWCA/

Bon Bon has a Pomeranian and Lyra Heartstrings has a black cat as pets.
Nothing in the show suggests this, but these kinds of pets seem to fit well enough.

Twilight Sparkle has developed a spell to understand animals.
Since she figured that it would really have helped with the Manticore and other beasts if she could understand what was all the fuss about. This is how she is able to understand Owlowiscious' "who"s.

Alternatively, Owl language is an actual language.
Owlowiscious seems pretty intelligent, possibly even sentient. Perhaps the same goes for all owls, and maybe Twilight's library has a book that allows one to self-teach Owl language, with all the distinct intonations of "who". Knowing Twilight Sparkle, she decided to learn it, just in case. And what do you know, it came handy!

All the other competitors were trying to help Rainbow Dash all along.
Look at that boulder pinning her wing. It's huge! Rainbow Dash is one of the strongest ponies in town, and she couldn't move it. So adding the efforts of a falcon and a bat isn't likely to budge it either. So instead of hanging back and being useless, they all flew for the finish line as fast as they could, knowing that the sooner they finished the race, the sooner Dash's friends would notice she's not with them and mount a rescue expedition.

Opalescence is a tom.
That's why Opal's so surly all the time, and puts up with Rarity's crud less and less: the poor mare's convinced her darling cat is as much of a girl as she is, when he really isn't.

Alternatively, Opalescence is constantly pregnant.
This could also explain her catty behavior. The "Puddy Tat" from "May the Best Pet Win" might even have been one of her kittens.

What happened to the other pets in "May the best pet win"?
Just some theories
 * Sweetie Belle eventually adopted that kitten
 * The Owl was given to a library pony in some other town.
 * the Toucan was given to the owner of a Canterlot nightclub, the Flamingo was given to one of the dancers who worked at the club.
 * the hummingbird and the three bugs all got jobs in the ponyville flowershop.
 * The Eagle found a home in Fillydelphia with a mare by the same of Stars n' stripes
 * The bat was given to princess Luna as a gift.
 * The Falcon found a home with prince Blueblood.
 * The ducks stayed with Fluttershy. They already had a nest together, and didn't want to leave.
 * The Bunnies also stayed
 * The seal realized that an aquatic mammal should not live in a forest, so he headed on over to the beach and met a seapony who adopted him. The Otters however, stayed behind.
 * The Flying squirrel stayed in his tree.

Owloysius is really a space alien working undercover.
He DID appear right after a meteor shower.

Fluttershy taught the eagle to imitate a red-tail.
She can teach a hummingbird to sing, so why not?

Angel was recovering from something during Putting Your Hoof Down.
He was still sore, and that's why he was nastier than usual.

Peewee will never be mentioned again.
Remember the other pets that were adopted during the show? Owloysius was introduced in Season 1 and never mentioned again until „May The Best Pet Win" to show us that RD was the only one without any pet. Then at the end of the episode RD adopted Tank who also disappeared right afterward. So what are the odds that Peewee will share the very same fate?
 * To be fair, Owloysius is a nocturnal creature, so, unless otherwise, they have the excuse he is actually sleeping during the day. With the anachronistic order of the episodes, Tank might not be adopted yet in any given episode.
 * There were epsiodes like Luna Eclipsed which took place during the night, but still no Owloysius. They don't even make any references to him. It's like he doesn't even excist outside of those two episodes mentioned above.
 * Have you guys ever heard of The Law of Conservation of Detail? Just because the characters are not mentioned, doesn't mean that they suddenly don't exist and are not going to be mentioned again.

Vinyl Scratch/DJ PON-3 is related to Rarity.
She's either her Cool Aunt or possibly her particularly youthful Hot Mom. They look vaguely similar, they're both unicorns (as is Sweetie Belle), and they're both artists. Also, it was implied in the pilot episodes that Pinkie and Rarity were friends before those events, which wasn't true of everypony. Pinkie doesn't seem to be the type that Rarity would hang out with without a mutual acquaintance, sure she'd go to her parties and maybe chat on occasion but that would probably be it. But if Rarity closely knew someone, like say a DJ Mom or Aunt, who would likely be on close terms with the main party-thrower of Ponyville then that's a different story. This would also explain where Sweetie Belle and Rarity's musical talents came from.
 * Partially jossed. We've seen Rarity and Sweetie Belle's parents in an episode.
 * How exactly do the pilot episodes imply that Rarity and Pinkie Pie were friends before the events? Sure Pinkie knew everypony in the town, but that didn't stop Rainbow Dash from finding her downright annoying until "Griffon the Brush-Off".

In the first season, we didn't see the true mane color of Vinyl Scratch aka DJ P0N-3.
She's a performer, and has to be entertaining. Since ponies usually don't wear clothing, her variation of wearing a wild costume is to just wear a different wig during each of her gigs. If we see the inside of her home/studio, there will be several wig stands, each with a different style sitting on it. What IS her correct mane color? You'll have to catch her when she's not behind a turnstile, setting up, or breaking down in order to find out.
 * Could tie in with the above mentioned "Scratch is related to Rarity" theory above and reveal that without her mane-dye/wig and shades...she looks exactly like Rarity (with a different cutie mark)!
 * What would give you that idea?

Vinyl Scrath is a Decepticon collaborator.
Her glasses are really a Minicon in disguise. She is secretly working to release Discord, or as the Transformers call him, The Fallen.
 * Alternatively, she's a genderbent Soundwave in Beast-form.

Lyra Heartstrings only came to Ponyville because of Twilight Sparkle.
If you watch the first episode, Lyra originally lived in Canterlot just like Twilight, and appeared to know her in some capacity given the ignored wave she gave her as Twilight was headed back to the library. But then when Twilight gets to her new home and Pinkie's thrown her a surprise party, Lyra's there with everypony else, and stayed in Ponyville instead of going home after the celebration ended. It's possible Lyra was a unicorn that knew about Twilight's immense magical power, and either wanted to be friends with her or had a mild crush on her. As such, when Twilight left, Lyra went to Ponyville herself, already planning on going there anyway for the Summer Sun Celebration but also hoping she could approach Twilight in a different setting. This never really got off the ground, whether because Lyra was too shy to go up to her directly or some other reason, but Lyra still remained a figure in the background for Twilight's life. However, at the party, she met Ditzy Doo and hit it off with her almost immediately. Then Ditzy introduced Lyra to her friend Bon Bon, and The rest is history. Lyra still might be Twilight's biggest unknown fan, however, which might explain why she always seems to be around when Twilight's doing something interesting.
 * Does that also apply for Amethyst Star/Sparkler and Minuette/Colgate? They were in Canterlot too when Twilight was, and were seen in Ponyville since.

Moondancer is the G1 Moondancer.
They're in Canterlot. G3 Moondancer was an Earth Pony, but Canterlot is inhabited apparently almost exclusively by Unicorns. It could be a Mythology Gag for older bronies, since anyone who doesn't know of G1 would just assume it's the newer Moondancer.
 * Given how many other G3 ponies were given wings or horns for their G4 update to even the numbers, G4 Moondancer might also be a mixture of the G1 and G3 versions, with G3's colors but a unicorn horn again. It would be a similar case as Twilight Sparkle, inspired first by G1's Twilight but colored like G3's Twilight Twinkle.

Expanding on a previous guess, many of the background ponies have families with Strong Family Resemblance.
This would provide an in-universe explanation for them appearing multiple times in the same scene.
 * Plausible. Consider also that the only defining physical characteristics of the ponies are their race, gender, color, eye color, mane and tail, and cutie mark. There are only three races, two genders (though there aren't many male ponies in the backgrounds. Or anywhere else), and a finite number of colors, so it should be expected that in a large crowd there should be some ponies who are identical save for their cutie marks and perhaps mane/tail style. But if you took a group of people and reduced them down to gender, hair color, eye color, and skin color you would get a lot of duplicates too, so this isn't entirely unrealistic.
 * Would this make Pinkie Pie a Chocolate Baby? (Or potentially adopted, at the very least?)

Octavia's childhood nickname is "Octie".
As such, Pinkie and the rest of their family refer to her as "Octie Pie".

Rarity is Bon Bon's Sitcom Arch Nemesis, but is completely unaware of it.
Bon Bon does take advantage of Applejack's willingness to give her free apples in apology for Apple Bloom's behavior, but that can be chalked up pretty easily to being mad about Apple Bloom trying to force apples on her for extra money. Less understandable is how she says she's never heard of Rarity, despite the fact Ponyville isn't terribly big and Rarity is one of her neighbors. It's possible this was just Bon Bon pushing Rarity's buttons because she doesn't like her for one reason or another. Rarity never talks to Bon Bon, so she's completely oblivious to this.

Lyra Heartstrings only speaks Italian.
It seemed a little strange that Lyra never had a speaking role at all despite having a number of background appearances. However, the Italian dub of FiM decided to have her Suddenly Voiced. Perhaps Italian is her native language?
 * She apparently also speaks Polish. Maybe English is the only language she can't speak?

Carrot Top is Equestria's answer to Bruce Lee.
Her official name is Golden Harvest. Why else would she be so badass in "Over a Barrel"?

Bon Bon is a voice actress.
Her voice is different in all of her appearances. Maybe she's doing some method acting, or possible just doing it as some kind of practice.

Bon Bon is Soulcatcher.
Her voice constantly changes, each time sounding like someone else's voice. Soulcatcher has many, many voices. Bon Bon's just using what she feels to be the most appropriate voice for the occasion.

Or Bon Bon is one of those ponies with Strong Family Resemblance mentioned above.
Two of the voices we heard are her mom and grandma.

Lyra's real name is Heartstrings.
But she goes by her nickname, Lyra, because it's a human name.

Lyra Heartstrings is a fan of the Daring Do series.
However, she only really reads the books for Ahuizotl, as he's her favorite character. Hands and everything.

Nocturnal Ponies.
In "Hurricane Fluttershy" there is a dark-blue pegasus with an Orion cutie mark, which indicates that his talent has something to do with appreciating the night sky. Has Princess Celestia been subtly preparing for Luna's return by guiding some ponies to prefer the night?

In a future episode, Octavia will talk.
And will be voiced by Grey DeLisle and another pony will be voiced by Cree Summer, add in Twilight Sparkle and it will be a little reunion of the three.

The Lyra in Canterlot is the real Lyra.
And the one in Ponyville is actually a Changeling!
 * I guess that also applies for Twinkleshine, Minuette, Lemon Hearts, and Amethyst Star?

DJ PON-3 is a vampire.
Pale, possibly red eyes, appears at the appropriate kinds of parties, we've never seen her in daylight.

Nurse Redheart's name is actually Nurse Sundance.
This is based on how Nurse Redheart's appearance seems to be based on the G1 pony Sundance.

Lyra wants Twilight's FRIENDSHIP
In her very first appearance she gives Twilight a friendly wave and looks disappointed when Twi just runs by and ignores her, we all know Lyra shows up almost everywhere Twilight does, and her toy in the wedding line, where everypony else has wedding gifts, Lyra comes with a picture of the Mane Six. Clearly, Lyra is Twilight's FRIENDSHIP stalker!

Bon-Bon is .
This would explain why she has so many different voices.

Derpy was a former alicorn, and the rightful heir to the throne

 * Which is why she has god-like powers that transcend Celestia's (time travel, immortality, immunity to poisoned muffins, the ability to appear in more than one place at once, and whatever that snowglobe thing was) and a unicorn daughter.

Derpy Doo is the Pony Version of the The Slender Man Mythos
A normal day while cleaning your attic, your collection of memories or what-you-get, you stumble in an photograph of a very private party last year. Almost burn to a crisp by an accident (odd) there is only a small spot still distinguishable. It takes you a moment to realize is Derpy Doo, a small acquaintance of one of your friends...probably. A normal pony at first sight, except you can't help feeling that there is something not quite right about her. Curious about it (it has been a slow week), you try to investigate about her but all your inquiries came to an abrut stop. Apparently all everypony know of her is her name and that she works in the Mail pony. Baffled at this (why she was invited to such party when nopony knows squat about her?), you take time to review the photograph of parties and small reunions of not only you but of your friends and family, the small ressure in the back of your head about this mystery becoming an irritation. Soon you realize (for the first time) that she is always present, in many occasions where she shouldn't, couldn't be there. In fact you don't remember how you meet her or inviting her to any reunion but she is always present, either floating or simply standing in the room, never interacting with other ponies as if she weren't there. While the small ressure in the back of your head become worse with each passing day, the desire to know who (or...what) is Derpy Doo transform from a small pique of curiosity to an obsesion. A pattern appears, a tragedy or injury befall a pony (in this lasts months, the six chosen) and she is always in the background, not quite watching like a emphasized shadow. Now the ressure so madenning, you decided to takle the problem head on but nopony knows where she lives (no surprising at this point) and her boss is as unhelpful as possible. You decide then to wait her in her morning route but no matter how early you wake up or even if you don't sleep, never see her enter or leave the Post Office and your letters keep appearing in your box, even when in desesperation you remove it and throw it in the floor, letters are sticking out as if mocking you. You snap. You try to forget but the ressure gets worse and worse so you leave Ponyville to some city who-know-where. You are a mess, can't remember when was the last time you eated or bathed or sleep more than half and hour and there is papers and papers around the house, insane rambling most of them and the ressure is like a shiv to your brain. In your table you ound an old portrait. Its from the time of the foundation of Poniville but your eyes are instantly glued to the small, almost invisible figure in the shadows, down in the woods. It is almost indistinguishible, void like shape except for its, looking straight at you, looking straight at you and you realize why that feeling in the back of your neck is so familiar and that she.
 * I always KNEW that pony was creepy! I knew it! I had a feeling! I must inform everyone of this! Quick! To the Fanfic Archives!

Ditzy Doo had a good reason to go west and north to get the southern birds for the Winter Wrap Ups.
Clearly, there's some kind of obstruction between Ponyville and the southern birds that makes the area tedious, difficult or even impossible to pass through around the time of Winter Wrap Up. During last year's Winter Wrap Up, the obstructed area was small enough for Ditzy to go west and make a U-turn to get to the southern birds, but by the following year's Winter Wrap Up (shown in episode 11) the obstructed area had grown to such a size that Ditzy had to go north and fly in a semicircle to get to the southern birds. Why do the other ponies think she went the wrong way both times, then? Well, the obstruction only developed after Ditzy took up the job of getting the southern birds for Winter Wrap Up, and Ditzy being ditzy, she never thought to say anything about it, making her going west and north look like mistakes.

Derpy Hooves will become a Heroic Bystander at some point.
It's a good way to give Derpy some focus, make her fans happy and let her be awesome, but at the same time ensure she doesn't outshine the main cast.

Derpy will get her own spin-off series.
However, it will only be available online and each episode is no longer than three minutes. The plot plot will most likely center on Derpy delivering and unusual package to an unusual location. Or of her doing stuff that was in the background while the Mane Cast do their thing, but in her relative POV this time.

There's nothing wrong with Derpy at all!
She can see all five dimensions just fine!

Spike becomes sick, forcing Derpy to deliver Twilight's letters
However, she's never delivered anything outside of Ponyville before, so the episode will center around her crazy hijinx.

Derpy has Duane syndrome.
Hey, it fits.
 * It could be some other form of strabismus.

Derpy's special talent is flying.

 * She was seen waiting to perform at the flight competition. She doesn't fly like Rainbow Dash, however. She's much more graceful and smooth, so her cutie mark has bubbles, to symbolize her ability to float with ease. She is a mail carrier because she can deliver delicate packages without damaging them.
 * Her cutie mark might represent bubbles of warm air, known as thermals, which soaring birds and gliders use to attain high altitudes.

Derpy Hooves has a huge family full of identical or similar relatives.
Every time we see more than one Derpy is because we see her sisters or cousins.
 * Same with Derpy with different colour of eyes or hair.
 * All names are canonical, one name can be true for more than one pony. So there are many ponies named Derpy Hooves, Ditzy Doo or even Bubbles (or other nicknames what animator gave them).
 * All interpretations are true:
 * There are many Derpies with Different level of intelligence or mental state.
 * One of them have one unicorn filly named Dinky.
 * This has most likely been Jossed in "Sisterhooves Social". Dinky's big sister is the grown-up unicorn Sparkler, known for leading the animal team in "Winter Wrap Up", and seen as an adult in at least one flashback. Derpy would have to be in her 50s to be Sparkler's mother, in which case she couldn't enter the Best Young Flyer Competition ("Sonic Rainboom") anymore.
 * I just handwaved the age issue as time travel. Derpy has a kid and does the sensible and responsible thing by dumping it on herself 20 or so years back (twice).
 * One (or more) is Doctor Whoof companion.
 * Few of them have mail related job.
 * Considering that Luna Eclipsed showed multiple grey-coated, yellow-maned pegasus mares wearing different costumes, I'd say this one is pretty close to confirmed. The one wearing paper bags who drained the apple barrel was the real Derpy Hooves (you can tell by the eyes) and the one dressed as a witch was her someone smarter sister.

Derpy Hooves is Celestia and Luna's mother.
If you watch "The Cutie-Mark Chronicles", you'll see Derpy on the lower left during Twilight Sparkle's flashback as Celestia is just about to raise the sun in Canterlot. She even has her characteristic derpy eyes. This means that despite appearances, Derpy is older than Twilight by quite a bit. However she hasn't aged a day between back then and now. This is because in actuality, Derpy Hooves is the depowered form of Celestia and Luna's mother, who gave up her powers and responsibilities as the one true god-ruler of Equestria thousands of years ago to her two favorite daughters as a gift when they earned their Cutie Marks. She's still alive because even after sacrificing her horn and all its magic, her body's still immortal. She was in Canterlot that day to watch Celestia raise the sun, something she does every year. This is also why Derpy was in Ponyville when Nightmare Moon returned.

Derpy's wall-eyed expression is because, even when she was the god-empress of equestria, she was known as being something of a Ditzy Genius / Cloudcuckoolander, when she gave up her magic and became a normal pegasus pony, the loss of all that magical grace made what once looked like a mildly ditzy expression into classic Derpy Hooves. Also Dinky is simply her first and only daughter since she gave up most of her magic, and Dinky is a unicorn because of the trace amounts of magic Derpy still has dormant inside her.
 * Alternatively, since we didn't see Derpy's cutie mark in that scene at the Summer Sun Celebration, it's also possible that she is about the same age as Twilight, or perhaps a little older, and was just at the Summer Sun Celebration in Canterlot as one of the celebrants, just like Twilight and all the other ponies who were there.

Derpy Hooves does not work for the post office.
She works for a moving company. We see her working for a moving company in "Feeling Pinkie Keen".
 * That potentially could still be a postal service like FedEx or UPS. Just they were delivering a lot of large packages to some address. Or Derpy could have just been helping Raindrops because Raindrops's normal partner was sick that day or something.
 * It could be a private parcel company, but it's more likely that it was what it appeared to be. After all, how many private parcel companies would ship something as large and heavy as a fully assembled piano? They would probably tell you to call a moving company. And why would she be helping Raindrops if Raindrops' partner was sick? It would be the company's responsibility to assign a replacement if necessary. Why would Derpy work for free just as a favor when she presumably has her own job and other responsibilities? The simplest explanation is that she works for a moving company.
 * Alternatively, she is a hire worker for her family's company in Canterlot, along with the Mule, Hayseed Turnip Truck and good Ol' Hayseed. May it be moving, a package service, selling muffins for the Sugarcube Corner, you name it.
 * Confirmed in "Last Roundup," wherein we see the postpony for Ponyville deliver Applejack's letter to the surprise party. Needless to say, he was not Derpy Hooves.
 * Ponyville could have more than one mailpony - maybe Derpy is the second mailpony in case the one we saw got sick or something.
 * We saw another mailpony in "Putting Your Hoof Down," the one Fluttershy shoved into the mailbox, and he was wearing the same uniform as the one we saw in "Last Roundup," which we have never seen Derpy wear. On top of which, that indicates that Ponyville, which is, after all, a small town, already has two mailponies at least. It seems exceedingly unlikely at this point that Derpy is also a mailpony.
 * She still can be the mailpony for the pegasi in town that lives on clouds, or a sort of "speed delivery" since flying wouldn't have the same obstacles as walking on ground.

Derpy Hooves/Ditzy Doo is related to Fattest Pony.
They're both Ensemble Darkponies with a derpy face, so why not?

The Mayor is Ditzy Doo's/Derpy Hooves's mother.
No idea how this came to me.

Ditzy Doo/Derpy Hooves is Scootaloo's older sister.
Given what we know of her, Scootaloo sees Rainbow Dash as the cool big sister that she'd like to have; the reason for this is that the sister she does have is a not-at-all awesome mailmare with wonky eyes and a poor sense of direction. We could well have a flashback that shows us that she saved Rainbow Dash at the cost of her depth perception, ability to focus on her job and intelligible speech.

Derpy Hooves is childless.
We see in "Sonic Rainboom" that she competed in the Best Young Flyer competition: she was the original contestant fifteen. Since the contest's name implies that entrants have to be below a certain age, we can reasonably infer that Derpy is pretty young, probably around the same age as the mane six. Given that, she would have had to marry very young to already have a foal of her own and to already be back in competition shape. So if there is any relationship between her and Dinky, it is probably not that of mother and foal.
 * Derpy could possibly be Dinky's foal-sitter, whom she calls "Mama" as a term of endearment.
 * But when have we ever seen Dinky call Derpy "Mama"?
 * Seemingly confirmed by "Sisterhooves Social," wherein we see Dinky competing in the race with a pony (Sparkler, supposedly) who is presumably her older sister, and who appears to be about Applejack and Rarity's age; there really is just no way somepony young enough to compete in the Best Young Flyer competition could have an adult child already.
 * There is a very simple explanation for this. Derpy is an ageless immortal, and both Sparkler and Derpy are her daughters. ANYONE who is trying to steal Dinky from Derpy is in allegiance with Discord.

Derpy Hooves is (the blond-haired veil of) UBOA.
Don't mess with the lights.

Derpy Hooves has crossed eyes because she is an all-seeing, all-knowing prophet.
She just doesn't realize that no-one else is.

Derpy Hooves and Ditzy Doo are not the same pony.
They are identical twins and Derpy had a head injury that screwed her eyes when they were fillies. You'll notice a lot of scenes where Derpy's eyes aren't cocked. They both have the cutie mark of bubbles because whatever their special talent is, it involves the bubbles. Perhaps they invented a new stamp glue together that can double as those Crayola play bubbles.
 * Original Guesser here, revising the Cutie Mark Meanings.
 * Derpy's bubbles reference bubble wrap, signalling how she can drop even fine china without shattering it.
 * Ditzy's bubbles are that stamp glue thing I said before.

Derpy Hooves and Ditzy Doo are sisters, or related.
In Winter Wrap Up, this dialogue occurs: "Rainbowshine: Ditzy Doo accidentally went north to get the southern birds!

Rainbow Dash: Oh that featherbrain. Didn't she learn her lesson last year when she went west?"

Later you see a Pegasus leading a flock of birds. She looks like Derpy, except she has purple hair instead of yellow. This is Ditzy Doo (she's bringing the southern birds), and since she looks like Derpy, she's her sister or related to Derpy in some way.

Derpy's health insurance won't cover surgery to correct her strabismus.
Think about it: for a predatory species whose eyes are close-set to provide the stereoscopic binocular vision necessary to gauge the distance to a target, strabismus can be a serious, even debilitating, problem. For an herbivorous herd animal like a pony, however, whose eyes are set on opposite sides of its face to provide all-around 360-degree vision so as to detect approaching predators, strabismus is really only a cosmetic problem; a pony does not have to worry about focusing both eyes on the same target, since it cannot anyway. Since it's only a cosmetic problem, her insurance carrier considers any surgery to correct it to be purely elective, and therefore will not cover it.

Most, if not all, of the more baffling things that Derpy does over the years are the direct result of a failed search for contact lenses.
As we've seen, Derpy turns up in the strangest places and is often seen looking rather foolish. While she does have a stereotypically-slow sounding voice, she might not be as full-on stupid as ultra-impatient loudmouth Rainbow Dash thinks she is. It could well be that most of her problems stem from her being not so much an imbecile as she is the local take on Mister Magoo: a pony of average intelligence cruelly hampered by defective vision. At one point, she lost her contacts (possibly during a Winter Wrap-up) and has been scrambling to find them ever since because her insurance won't pay for replacements.

Derpy Hooves is hearing-impaired.
You will no doubt have noticed that the only way to get her attention or have her follow any sort of commands is to look straight at her and have heard her slow, deliberate and somewhat stilted way of speaking. It could well be that her trademark clumsiness is the result of her getting carried away because nopony usually asks the deaf Pegasus for her help all that often.
 * Her voice seems to have the same sort of inflection quirks that pop up when one can't reference their own or other voices, and maybe whatever made her deaf threw off her equilibrium. The eye, is her eye, not much more to that.
 * Her clumsiness might also be the result of an inner ear problem. Which isn't helped by a visual impairment either.

Derpy is not a pony, but a disease.
Ditzy Doo is "patient zero". Symptoms include Derpy Eyes, Muffin addiction, scrambled sense of direction.
 * Screwball is also infected.

"Hooves" is Derpy's married name.
But it's actually spelled "Whooves." She's married to the Doctor, who is Dinky's father.

"Derpy" is so embarrased by her real name, she calls herself Derpy Hooves because she feels that it's less humiliating.
When you stop and think about it, there's no real reason that a pony would willingly allow herself to be called by a rather nasty little name unless the alternative is so much worse, something that implies that she's stupid when she's not is seen as a step up; this means that, much like a human named Forsythe P. Jones calls himself a word that used to mean "imbecile" before it came to mean "tall, skinny kid who eats burgers", the pony we call "Derpy" not only lives in constant fear that somepony out there will discover her real name, she's hoping that what used to mean "wall-eyed dolt" will come to mean "grey Pegasus pony who eats muffins."

Derpy Hooves/Ditzy Doo is a close friend of Hoity Toity.
This is why Derpy, Lyra Heartstrings, and Bon Bon can be seen clearly at all of these well-to-do fashion shows Photo Finish puts on despite being plain old ponyville residents; Derps is a friend, so she and her pals can get into big events thanks to Hoity Toity pulling some strings. Derpy might do advertising for Hoity when the mail's having a slow month.

Derpy Hooves is Ditzy Doo's Appropriated Appellation.
It was a nickname given to her by the same colts who made fun of Rainbow Dash and Fluttershy as foals, due to her simple-mindedness and her eyes. However, she decided she liked it, and started asking everypony to call her that.

If she can't already, she'll be able to shoot lasers from her eyes.
Hey, why not?

Like Scootaloo is with Rainbow Dash, Dinky Hooves is obsessed with Derpy Hooves.
Since we know there not sisters, maybe Dinky idolizes Derpy and modified her appearance to be more like her.

Derpy is not actually as young as her presence in the Young Flier's Competition would indicate.
Rather, the contest is simply a contest for non-professional fliers with a non-indicative Name. Most entrants are not professionals because they're too young to have made it, but a few older ponies who have no interest in professional flying/racing enter too. She's actually in her late 40's or early 50's, or the pony equivalent thereof, old enough to have a fully or mostly grown daughter as well as Dinky. We know from seeing Rarity's young-looking parents that ponies age very well and don't show signs of it as quickly as do humans.
 * Alternatively, if you take the "Derpy has Special Needs" character interpretation, it might be that they don't have a Special Olympics-type contest, and the Young Flier Competition is used for that instead.
 * Alternatively alternatively, she's just so scatterbrained that she didn't notice that she was too old for the contest, and the registration thing failed to pick up on it until it was too late.

Derpy's Cutie Mark...
...is bubbles because Derpy is a bubblehead. And suddenly it all makes sense.

Derpy's Cutie Mark...
...symbolises how fragile she considers the world to be. Notice how easily she wrecked the town hall? She just touched it. Needless to say, she's not very fond of her special talent.
 * This is also how she met the Doctor - she accidentally broke time.

Derpy Hooves does not especially love muffins.
Yes, granted, she was one of the many ponies who assembled to try the muffin samples in "Applebuck Season," and she may even have been the one to say "muffins," but there were a lot of ponies there; many of them were licking their lips and drooling, but Derpy was not. She was also not one of the sick ponies later at Ponyville Urgent Care, suggesting that she in the end didn't have any of the muffins.
 * Blasphemy!! I approve!
 * Alternatively: She's so muffin-obsessed that she has muffin-senses. She sensed something horribly wrong with the muffins and as such wasn't overeager like her less-enlightened peers, tasted one calmly without swallowing or spitting, left the visible area, then spat it into a garbage pail to be polite.
 * But then why didn't she warn anypony else? That seems rather thoughtless of her. Isn't the simple explanation that she didn't have any?
 * Simple, those asinine ponies would not have listened to "stupid" Derpy's warnings, and then all suffered their "just desserts" (even though muffins are a breakfast food)

"Derpy Hooves" is a Reality Warper Eldritch Abomination locked outside of time and space.
In The Cutie Pox, we see "Derpy" in the form of a filly when she should be an adut. Derp eyes also appear on other characters as well, such as on Pinkie Pie when she is suffering from Sanity Slippage. Also, there are frequent instances of ponies that look almost exactly like "Derpy," minus the Derp eyes.

I hereby propose that "Derpy Hooves" is actually an extradimensional horror a la Yog-Sothoth, which is beyond omnipotent and omniscient, but cannot fully manifest a physical form in the material universe. Instead, it manifests itself by altering reality on a fundamental level, turning a pony into an avatar of itself. When this happens, the altered pony will possess Derp eyes and become an agent of completely random and inexplicable events that further the goals of Derpy Hooves. Being an Eldritch Abomination, these goals are incomprehensible to ordinary Ponies or Humans. We only catch a glimpse of the true horror and insanity before the manifestation inexplicably vanishes again without a trace. The duration of the manifestation can vary, from an extended period of time to a mere split second, such as when Derpy temporarily manifested as Rainbow Dash in Fall Weather Friends.

There is more, however. When Derpy Hooves alters reality to create an avatar, it also retroactively alters the timeline. The altered pony will, after Derpy's manifestation, have always possessed Derp eyes ever since birth. This is part of why absolutely nopony ever points out said Derp eyes: as far as they're concerned, that's the way it always was and therefore they have become accustomed to it. Similarly, when Derpy releases its manifestation in the physical world, the timeline changes again, the Derpy avatar returns to normal, and it is as if nothing had ever happened. However, the Human audience viewing the show is capable of observing events from outside of the Equestrian timeline. This is why we can notice Derpy's various appearances.

There is, as pointed out, a large population of ponies that closely resemble "Derpy Hooves", sans Derp eyes. There are multiple ways to explain their presence, and why the most commonly seen form of "Derpy Hooves" resembles them: Explanation 1: The Derpy clones are in fact descended from the first manifestation of Derpy Hooves. Thus, this makes them easier targets for the Derpy Hooves entity to alter, and hence why it almost always appears in such a form. Explanation 2: The physical appearance of the Derpy clones is a simple coincidence. The Derpy One simply prefers such an appearance and chooses to alter such ponies when possible. It is also possible that Derpy altered reality purely for the purpose of creating a high proportion of suitable avatars in the pony population. Explanation 3: The Derpy clones are actually the results of Derpy's manifestations. When The Derpy One manifests and then releases its avatar, the pony in question is not restored to its previous form but instead is turned into a Derpy clone. There may be some ulterior purpose to the creation of said clones, as well. This raises some questions as to how Mane Cast members such as Rainbow Dash and Pinkie Pie remained unchanged. It's possible the transformation was prevented by the Elements of Harmony. This raises a question: how many of the Derpy clones had friends that don't remember them anymore? What if one or more of them was a friend of the Mane Cast?

Also, a certain pony, Carrot Top, is frequently seen accompanying the Derpy avatars. There are two explanations for this. Explanation 1: Carrot Top is High Priestess to The Derpy One, Prophet of Doom, and Herald of Armageddon.// Explanation 2: Carrot Top is aware of The Derpy One's existence. She opposes The Derpy One by providing its avatars with a certain irresistable foodstuff that incidentally inhibits their abilities and intelligence, preventing chaos from being unleashed upon the world. The food in question? Muffins.// Addendum 2.5: After extensive contact with Carrot Top through multiple manifestations, the Derpy avatars have begun developing a new personality which is friendly towards her, and therefore will possibly serve her instead of The Derpy One's will. This is EXACTLY according to Carrot Top's plans.

TL,DR: Derpy Hooves is actually not one pony but an Eldritch Abomination that manifests through Derp eyes. Said manifestations become much easiler on targets going through Sanity Slippage. If you make a Derp face, you risk being erased from existence and replaced with a Derpy clone. And no one will ever notice. After all, you never existed.Fortunately, Carrot Top is working to oppose Derpy and defeat it with The Power of Friendship.
 * Derpy seems awfully friendly and well-meaning, if clumsy, for an Eldritch Abomination.

Derpy is an immortal time traveler.
I don't know how or why, nor do I know whether or not Doctor Whooves is involved in this, but it's the only logical explanation of the available facts (that doesn't render her a lovecraftian horror.) One day as a fill, Derpy wondered what sort of children she would one day have and traveled forward in time to meet and hang out with Dinky for a day.
 * Its all about Pime Taradoxs

Derpy is a hypercompetent secret agent.
Her job as a mailmare is just a cover. Celestia sent her to Ponyville undercover in order to keep an eye on Twilight Sparkle and company. She watches them and writes weekly reports, using her position in the postal service to deliver them to Celestia covertly. If the situation calls for it, she's use her mad secret agent skillz to help out offscreen. Where was she during Nightmare Moon's return? Why, she was visitng the moon to destroy her Kill Sat! Where was she during Discord's return? Why, she was single-hoofedly defending Canterlot from an army of Discorded ponies! All her little personality quirks are still intact, she's just also a highly competent secret agent.

Derpy runs in elite Canterlot circles.
It has previously been suggested that Derpy is friends with Photo Finish, given Derpy's prime seat at the fashion show. Now, Derpy is seen in one of the squares during Rarity's "The Pony Every Pony Should Know" song. Derpy's got friends in high places.
 * She was at the Grand Galloping Gala, so that would fit.

Ditzy Doo is actually a brilliant philosopher and scholar, but is absent-minded.
When Rainbow Dash called her a "feather-brain" in "Winter Wrap-Up," she wasn't implying that Ditzy was stupid. Rather, Ditzy is brilliant, but she is, as such, also very absent-minded. She flew north to get the southern birds, and west the year before that, because she was contemplating the epistemology of morals or the standard model of particle physics, or some other abstruse subject, and wasn't paying attention to what she was doing.

Derpy Hooves/Ditzy Doo is a well-known performance artist.
Given that we know that she loves fashion and is seems to be part of Canterlot society, it could well be that her wearing paper bags isn't so much the result of brain damage but a pseudo-intellectual comment on how ponies have been reduced to commodities in the consumer society. Also, she wasn't actually delivering furniture when she pelted Twilight with all that stuff in Feeling Pinkie Keen; what happened is that one of her installations got crashed by a unicorn spying on an Earth pony.

Derpy Hooves is actually Princess Cadence doing a run-away bride thing.
As we've learned, the Season Two closeout is a Shout-Out to the recent royal wedding. It could be possible that most of the second half of the season would have as a linking theme the need to find a bride with a severe case of the jitters. Eventually, of course, her disguise as a cross-eyed Pegasus pony would slip and we'd be off to the races.

Derpy is a deep-cover operative for some Guardian of the Multiverse organization.
She is to scout out threats as they appear. She is also ordered to display Obfuscating Stupidity to maintain her cover.

Amethyst Star isn't related to Dinky.
It could be that Dinky really wanted to compete in the Sisterhooves Social but was sad that she had no sister. Amethyst, a foal-sitter that Derpy hired for the day, competed with her. It would explain her appearance with another foal in the Mare-Do-Well episode where they were having a picnic.
 * Maybe she's her magic tutor? Derpy can't teach her.

Derpy Hooves died from eating Applejack's "baked bads".
Notice how in the crowd we see Derpy, but when it shows the sick ponies, Derpy is gone. She must've eaten more muffins than the other ponies, so was affected quicker. All those times we saw Derpy in the episodes afterwards? That's either her ghost, or a friend who decided to paint herself gray and change her cutie mark to look like her friend, because of how much she missed Derpy.
 * Alternatively, she's perfectly fine. Over the course of her life she's eaten so many bad muffins that she has Acquired Muffin Immunity.
 * Maybe eating so many of the muffins are what caused her to become cross-eyed in her later appearances.

The "filly Derpy" seen in "The Cutie Pox" is Derpy Hooves.
Whether there was a timey-wimey accident involving Doctor Whooves, or a accidental/purposeful Fountain of Youth spell/potion/whatever by Twilight/Zecora/whoever, I wouldn't know.

At the end of Feeling Pinkie Keen, Derpy was applying for another job.
It's a wonder Twilight wasn't killed in the avalanche of stuff earlier.

Derpy appeared three or four times in "Heart's Warming Eve"...
To please people if they couldn't include in in the next few episodes like "Baby Cakes" (Unless you count the baby in the nursery that had her hair like the "Cutie Pox" example above)

Derpy is a stoner.
I'm very surprised this hasn't been posted yet actually. It's kinda obvious that Derpy uses medicinal marijuana (Probably for her eyes). It would explain her general behavior. Also, she's got bubbles for a cutie mark. Not to mention that she's addicted to muffins, which work great as "munchies". It's also possible that the entire show is an extended hallucination and she imagines herself and the people around her as ponies. Magic ponies.

Derpy's Cutie Mark signifies "Area of Effect."
In her first "starring" scene (in "The Last Roundup"), Derpy was shown to unintentionally cause damage to herself and the material around her. Some was due to sheer incompetence, like her constant stomping of the thundercloud, but some doesn't make sense in that regard. In particular, how come that one spot where she sat collapsed? None of the damage she caused seemed to affect that particular spot. However, what if Derpy's special talent was simply being jinxed and unintentionally jinxing everything around her? This gives some meaning to her bubbly Cutie Mark - bubbles could signify the area of effect that this "bad luck" generates.

Derpy is the pony version of Xatu.
It's said about Xatu that its right eye views the future while the left eye views the past - maybe Derpy's eyes are that way so she can see the past and future at the same time! Time travel abilities can also apply here, since Derpy was seen as she is now in Twilight's flashback in "Cutie Mark Chronicles", but appears as a filly in "The Cutie Pox" - all that time traveling thus allows her to see in the past and future at will, but she also has to stay partially focused on the present, hence her eye difference and seeming lack of coordination. She could also be able to look into other dimensions as well as the past and future.

Derpy is suffering from pegasi Power Incontinence
It seems obvious, that pegasi have magic powers related to gravity - they can pull (and stop) vehicles in mid-air, fly on wings that are obviously to small, jump on clouds and completely ignore most laws of physics once they break the sound barrier. Derpy can fly and cloudwalk too, but she breaks everything she bumps into (and at one point - sits on) - as if she was much heavier than she is.

Dinky's true parentage was revealed in "Last Roundup"!
If you look here at about 3:36, right when Applejack is saying "little," (Here is the relevant screencap) the camera stops on Dinky, gazing up at a white-coated, purple-maned unicorn stallion, who is gazing down at her with paternal affection. I submit that that is Dinky's father. Note also that Golden Harvest, called Carrot Top by some, is standing on the other side of Dinky. I further submit that Golden Harvest is Dinky's real mother! Derpy is not Dinky's mother, but she is Golden Harvest's best friend, and as such is like a favorite aunt to Dinky. That's why Derpy was at the Sisterhooves Social: to cheer on her favorite "nieces"!
 * I never did much see Derpy as being Dinky's mother, especially with Sparkler in Sisterhooves Social being quite a bit older than Dinky, and Derpy seems as old as the Mane 6. This theory, however, makes quite a bit of sense, I approve!

Derpy is Rainbow Dash's Autistic Older/Twin Sister
First Derpy isn't retarded, she just has moderate HFA and is of average/above average intelligence, but she lacks common sense, her voice lacks proper intonation, her verbal thought process and speech is slow, and she is very clumsy (and she has stromboisis or however you spell it). This is still disabling enough that she does not get much respect from her younger sister, Rainbow Dash. Faust has stated that RD doesn't have any younger siblings as she would make a poor older sister, but that does not disqualify her from having an older or twin sister. The two pegasi both have the same mane and body shape, they are both a bit tomboyish, and it is clear from the Last Round Up that they know each other fairly well. Even though Derpy is older or the same age Rainbow still feels like she is her responsibility due to her disabilities. Rainbow Dash was drawn to Fluttershy in summer flight camp because she reminded her of her sister. Eventually Derpy was sent to Ponyville for it's autistic social skills program for adults which may have included some of our other ponies, and Rainbow Dash moved with her because she was so loyal.

Derpy is actually Rainbow Dash's Split Personality.
You think Pinkie Pie was the only one with a Split Personality? Think again. Ever notice how the only time they've really interacted with each other in canon was at the beginning of The Last Roundup? and even then, they only seemed to be just the two of them. Perhaps it's a case of Unreliable Narrator and in reality, it was Rainbow Dash who damaged the town hall (She does fly into buildings alot, just ask Rarity). Why does she have a alternate personality that's so... Uncool? Rainbow Dash became so "cool" that her "uncoolness" was purged and then manifested itself into another pegasus that was everything not Rainbow Dash, "Derpy".
 * 'DO WANT!!! I LIKE IT!!

Discord turned Derpy into a first-class sadist.
In The Last Roundup, she was really concerned when Rainbow Dash fell through the boards, and we know she is eager to help; things go wrong, but she really wants to help. And we know Discord inverted many ponies' personalities. So Discord would have made her a nasty character whose plans to make ponies hurt worked well.

The "Daring Do" adventure novels are actually ghost-written by Derpy
And Daring is actually her Mary Sue Author Avatar. Both ponies are pegasuses (pegasii?). Derpy is pale grey with a light yellow mane, whereas Daring is dark yellow with a dark grey mane. Derpy's eyes are yellow, and Daring has purple eyes--the complementary color to yellow! And Lauren Faust originally intended to give Derpy the name "Ditzy-Doo". We don't really know what Derpy's talent is (aside from breaking things and enjoying muffins)--perhaps she has a house full of broken typewriters from writing some manuscripts...

The toyline pony Lily Blossom is a relative of Derpy's
They're both pegasi, and they have a very similar color scheme.

If "The Pony formally known as Derpy" ever makes a speaking appearance once more, her personality will get a Retool.
It's doubtful if it'll ever happen again, but I'd imagine that if they ever decided to introduce her again, she won't act the same way she did in "The Last Roundup". She'll be the same Ditzy character, but she won't rely on slapstick. I'd imagine that her being an Expy of Dory from Finding Nemo would be a good fit for her character.

She's NOT a mail pony (sorry).
By the 19th episode of the Season 2, we have seen two other mail ponies, and no mail deliveries by Derpy.
 * However, this doesn't mean she isn't employed with a moving and/or delivery company of another kind (as seen during Season 1).

Derpy was born during Discord's initial reign.
Makes perfect sense... Kind of...

Derpy's first name is actually "Derby."
Derby makes much more sense as a pony's name, since a derby is a kind of horse race. But because the 'p' and 'b' sounds are closely related, she would pronounce her name with a 'p' when she was younger, and it stuck.

The name "Derpy" is still canon.
After Derpygate a lot of people considered the name Derpy not to be canon anymore, some people even claiming that Ditzy was now the canon name. However, the name Ditzy wasn't used in the edited version of "The Last Roundup", instead there was no name used at all. And the name "Derpy" was (after some tense moments) kept on all the We Love Fine merchandise. So "Derpy" is still the only name ever given to the character in anything actually released to the public, making it still canon until further notice. To keep it that way, they'll just have to not call her by any name in the rest of her appearances. On a related note...

If Derpy's role is ever expanded again, her mother-daughter relationship with Dinky will be made canon.
She can then simply be referred to as "Dinky's mom" by the show from now on.

Derpy is extremely strong, even for a pony
She was able to break the town hall with just her butt. And then there's her scene in Feeling Pinkie Keen. Sure, she dropped them due to her clumsiness, but why would she be expected to lift heavy items like a piano to begin with unless she's quite powerful? Take a look at the gruff looking "boss" pony glaring at her after she drops the items - he looks way stronger, so why didn't he take the piano? And why employ a noted klutz like Derpy to deliver heavy objects to begin with? Because if she can overcome her tendencies for a while, she's more than buff enough to do it.

Derpy/Ditzy's real name is Dipsy Doodle
Nopony uses it, and most ponies don't even know Derpy/Ditzy is a nickname.
 * This is why she hangs out with Carrot Top/Golden Harvest.

Derpy's has a celebrity relative
Named Johnny Derp

And the Doctor Whoof companions (curent,past or future)are

 * Derpy - popular fanfic companions (she can be somepony like Rose or Donna)
 * Twilight - another companion from fanfics
 * Pinkie Pie. See her own WMG page for why.
 * Rarity and Fluttershy - just look at part when they are singing in Winter Wrap Up with Doctor Whooves, it must be some connection.
 * Fluttershy's case may go deeper; look at her part of at the Gala, she's propably the companion of 5th Doctor, propably (jugding how they look at each other) romantic relationship
 * Fluttershy might also have traveled with the Tenth Doctor. She fears her own shadow because she knows of the Vashta Nerada. She might actually be the Ponyverse's version of Donna Noble.
 * Colgate/Romana - fellow Time Pony.
 * Colgate could be the Ponyverse's version of Susan Foreman.
 * Rose/Roseluck - Should be obvious.

Doctor Whooves isn't the Doctor....
He is actually Doc Brown from Back to The Future! There are several possible reasons for this. Firstly, the mane is actually brown, so that suits the name, secondly, his voice actor does have far more of an american accent and does quite old, especialy compared to either of the most recent Doctors. Think of the fan-fic possibilities!
 * Then where is Marty McFly, and how did the Doc become a pony? Maybe Marty went a little too far into the past with the DeLorean and altered the flow of evolution so that ponies and not humans became the dominant species? Hmm, now we need a Fanfic in which Marty and Pony!Doc Brown try to restore the original timeline while the Mane Six try to stop them to save Equestria!
 * And Marty McFly is, of course, a pegasus.

Doctor Whooves is The Doctor from the Doctor Who universe
His perception filter now affects us because we're not watching Doctor Who, in which the audience, theoretically, travels with the TARDIS, making him appear to be a pony. Also he has died since visiting Ponyville, sometime between Winter Wrap Up and The Sonic Rainboom, and regenerated from an earth pony into a pegasus.

Dr. Whooves isn't the Time Lord, he's the companion
Which means DERPY is the real time lord!

Dr. Whooves and Discord have fought each other many times over the course of Equestria's history.
It's only natural to come to this conclusion since these two characters are heavly asscoiated with 2 of the most famous works of science fiction. Fanfics based on such clashes is inevitable.
 * Then why isn't Dr. Whooves helping the mane six against Discord now?
 * Because he isn't yet an official character, due to the majority of the series having been made before the show crew caught onto the fandom and memes. Just give it some time.
 * Which is the Doylist explanation. Watsonian explanations include "fixed point in time", "wants to give the girls to grow and learn and is secretly on the sidelines in case all six of them fall", "is elsewhere by sheer dumb luck", "is else when by sheer dumb luck", and "is out and about trying to mitigate the damage all the Chaos Storms are causing while the Elements head to the source".

Dr. Whooves ISN'T a literal incarnation of his namesake.
At least not canonically; if he were ever to have a real role in the show, it would be quite impossible for his portrayal to be the same as it is in fanfics, due to the obvious copyright issues. As a nod to the fandom, though, he would still at least be an Homage Expy of the actual Doctor, in the vein of Professor Paradox

Romana/Colgate is actually a pony version of Romana III.
Yes she is third version of time lord companion of The Doctor. That version will show up in future episodes. And she will be somehow related to toothpaste.

Dr. Whooves is actually a TARDIS rather than a Time Lord.
We all know that TARDISes are living entities capable of taking on all manner of shapes and forms. Their Chameleon Circuits, upon first arrival in a world, analyze everything on the planet within the first nanosecond and adjust their form to blend in. And what blends in more perfectly on Equestria than a pony?

This is also how he was able to grow wings for the Best Young Fliers competition; a simple adjustment to the appearance. As for how nopony noticed this sudden change? 2 words: Perception filter.

Hourglass Cutie Marks do not depict Time Lords.
They depict Time Lords and companions. Dr. Whooves is a ponified Time Lord, but he's got a large number of companions, past present and future that hang out in Ponyville.
 * Alternatively, they are also a larger population of time travellers. We'll be seeing Doc Brown, Sam Becket, The Terminator, etc.

Doctor Whooves is the real first incarnation of the Doctor.
All of My Little Pony Friendship Is Magic predates (as well as after and alongside) the events of Doctor Who and one day Doctor Whoof will regenerate into William Hartnell.

That isn't The Doctor
He's merely the guy that plays him on TV.

Doctor Whooves will eventually be seen with a female pony whose cutie mark is an explosion.
She will have two saddlebags; one full of some strange cans and the other with a baseball bat sticking out.

Fleur de Lis (Fancypants' escort in "Sweet and Elite") is actually Susan Foreman, the Doctor's granddaughter.
This may be a bit far-fetched, but Fleur de Lis' Cutie Mark are three heraldic lilys. The origin of the name Susan is the Persian word sousan, which also means lily.
 * Except that Susan actually comes from the Hebrew name Shoshannah, meaning rose.

Doctor Whooves got first place in the Running of the Leaves
Why not?

Doctor Whoof is a doctor
We know this show has a habit of subverting expectations with shout outs. So Doctor Whoof isnt based on The Doctor but The Doctor

Doctor Whooves and his Pegasus lookalike in Sonic Rainboom are half-brothers.
Their father was a notorious Don Juan.

Time is being rewritten.
Rainbow Dash has never called anypony "Derpy". Only the Doctor, Ditzy herself, the Silence and a few other ponies remember otherwise.

Doctor Whooves is under the effects of a Chameleon Arch.
He didn't believe it when Twilight told everypony about time travel, and he RAN from the Changelings. Obviously, he's Not Himself. The answer? Chameleon Arch! Derpy has his watch, which has been enchanted so even she can't lose it.
 * Wait, are you saying the Doctor wouldn't run? Running is what the Doctor does best.

The entire "battle" between the Buffalo and the Apple-loosians was staged. Mostly.
Both sides got the message behind Pinkie Pie's bizzare and narmy preformance, but agreed that it was lousy. Perhaps they also agreed stage a dramatic showdown at high noon and not tell the ponies (as well as Braeburn and Little Strongheart for some reason) about it. It also seems unusual that they would use Pies as ammunition. However, perhaps the Buffalo got a little carried away with their stampeding…

The Royal Guards will appear a lot more often…
…as Red Shirts.

Most (if not all) of the disasters in "The Mysterious Mare Do Well" were the result of an elaborate conspiracy.
The mastermind was either Derpy, Amethyst Star/Sparkler, or the Mayor.
 * It was all an elaborate insurance fraud set up by all three of them. Mayor Mare planned it out, while Derpy covertly damaged the dam and tampered with the construction site machinery. Sparkler ran interference in case Rainbow Dash would need to be distracted.

Some ponies will get A Day in the Limelight.

 * Derpy/Ditzy: Mostly for the fans.
 * Doctor Whooves: The entire episode will be an Affectionate Parody of Doctor Who.
 * And it will be awesome.
 * Prince Blueblood: Revolving around him going to Ponyville for a day. Humiliation Ensues.
 * Maybe Celestia decides that Blueblood is too much of a good-for-nothing waster, cuts his finances and sends him to Ponyville to teach him some decency and humility.
 * Trixie: Perhaps even getting a legitimate victory.
 * Gilda: Why not?

The Mare Do Well will reappear as a separate character
Another pony dons the costume, but out of purely selfish motivations. Either out of a selfish desire for heroism or to outshine the mane cast on purpose (Trixie would actually be perfect for that I guess…). Either way, unlike the Mane Cast, this one will cause disasters for herself to handle.
 * Either that, or as a Captain Ersatz of Batman, right down to the origin story (albeit a Lighter and Softer version befitting a TV-Y show).

The Mayor will try to become Mare Do Well.
Because it would be very funny.
 * Bonus points if she discovers that despite not having the raw power of the 'original' it's actually something she's good at.

There will be an Anti-Mare Do Well.
Mostly because of this picture. A suggested name for the culprit is "Ne'er Do Well" (like in the comments).

The statues in the Sculpture Garden are made from cannibals and rapists.
Hence Discord's line about turning ponies to stone.
 * Given that they represent certain virtues, you'll probably have to include warped versions of said virtues. Victory, for instance, should belong to a War Criminal.
 * Also, why wouldn't Celestia just have them executed in that case?
 * same reason she didn't execute Discord or Nightmare Moon. maybe execution is illegal in equestria?
 * The reason those two were trapped was because they were immortal gods, so killing them would be impossible.
 * Why would she turn them into stone instead of throwing them into a prison? In a prison they eventually die. As a statue, they are trapped at the same spot, unable to move but still conscious for all eternity. Sure it’s hard to feel sorry for rapists or cannibals but Celestia doesn’t strikes me as the kind of ruler who would torture anypony, not even the worst scum.

Miss Jubilee is an Expy of the G1 pony Cherries Jubilee.

 * Possible...

The pony who barked like a dog in "Read It and Weep" acts like she does thanks to leftover damage from Discord.

 * Remember Big Macintosh acting like a dog-mole? It seems the World-Healing Wave didn't quite fix the whole world...

The barking pony's talent/destiny is not insanity
Despite her cutie mark being a screw. She sold screws and other hardware fixtures before going insane.
 * Righty-Tighty was once known for her ability to keep cool under stress, which was actually quite useful in a construction foremare. Unfortunately...well, see previous WMG. Poor filly never snapped back.

The funeral briefly seen in "Hearts and Hooves Day" was for the cancer pony from "Read It and Weep".
He didn't make it... :(
 * I second the motion.
 * Sweetie Belle, you little jerk.

That mule in "Applebuck season" was Matilda's son
At some point she got tired of waiting for Cranky and there don't really seem to be any other donkeys in Ponyville.
 * And yes, I do know that the offspring of a stallion and a jenny is technically called a "hinney" but what's the difference?

Cranky Doodle Donkey is Tommy Westphall
He's got the snow globe. And boy oh boy, the implications...

The Screw cutie marks aren't their real marks.
When somepony goes insane enough to be institutionalized for an unknown period of time, a patch with a false cutie mark is placed over their flank in order to afford them some anonymoity. That cuts down their chances of being recognized, so once they recover, there's less chance of dealing with the social stigmata of being seen as "that crazy pony".
 * Alternately, if you're too far gone mentally, your mark will actually change on its own as a sign to the world that you need help.

The bald yellow stallion from "Read it and Weep" doesn't have cancer.
That's just Curb Stomp, Poneyville's resident skinhead; his Cutie Mark, had it been visible, would be a pair of crossed hammers. He landed in the hospital after having the crap kicked out of him by a couple of bulls who took offense to his views on pony supremacy. As for the whole "stealing my slippers" thing, he was recovering from a concussion, and a bit confused. (Besides what won't a zebra steal, other than your job? And the llamas are sneaking across the border to steal those. Am I right or am I right? Horse Power!) Watch out for Curb Stomp in his upcoming Day in The Limelight episode, Equestrian History X.

Crackle is a Retired Badass.
Crackle isn't a teenager, but rather an old and unusually small but fierce dragon who has spent a lifetime terrorizing Equestria and other communities. The teenagers don't take him seriously because he's old and doesn't do much of anything anymore. Rarity's costume was designed after an old painting she had seen in Canterlot, painted in the days when Crackle was a menace to Equestria.

The Mule is going to snap
There's only so long someone can be the butt of racist terminology.

Crackle is actually a mutant dragon. Specifically......
She's living proof to other dragons why COUSINS SHOULD NOT HAVE KIDS WITH EACH OTHER. Even among all the teenage dragons, who each have an unique design, Crackle has a Non Standard Character Design, with having eight legs, bulging misaligned eyes, morbidly tiny wings, and covered in growths with eventually harden into cysts that can be functionally counted like the jewels that are very commonly dug up in Equestria. Due to dragons beings extremely powerful, immortal beings with probably massive amounts of latent magic with drastic growth spurts if their natural greed kicks in and goes unchecked, their genetics is all sorts of wonky and any sort of major deviation from a normal sequence can end up with something truly drastic, making dragons far more suseptible to birth defects and thus far greater taboo about incest than other races. However, from Garble's rather casual reaction to Rarity's disguise after being reminded by another dragon about Crackle, it can be shown that while incestual relationships are considered taboo, it still happens on an uncommon scale.

Steven Magnet is Spike's father.
They both are purple, wingless, have a fondness for mustaches and Rarity. Possibly Steven had a relationship with Spike's mother which ended badly (possibly with the mother realizing she was The Beard). Spike's mother gave up the egg for adoption/abandoned it and never told Steven.

Joe's full title is Donut Pony Joe.
He's called "Pony Joe" in his first appearance and "Donut Joe" in his second appearance, so perhaps these are two shortenings of the same thing.

Joe is indeed a super spy.
His cover is a donut chef.

No, it's Mulia Mild who really is, or was, the super spy!
Because she's obviously an expy of Julia Child, who was a member of the OSS during World War Two. So Mulia was an agent of the Office of Strategic Stallions, which was led by Wild Bull Donovan. After the war, it became the Canterlot Intelligence Agency, and Mulia became a chef.

Pinkie Pie was half-right about all three rivals chefs.
Donut Pony Joe is indeed a super spy, but the stale beer and leather jacket kind, Mulia Mild is a ninja, who does her work by infiltrating as a caterer, and Gustav is a villain, who runs his criminal empire out of his kitchen. Usually, none of them would risk their cover by engaging in such ostentatious activities, but it was an odd trip.

The white pegasus in Hurricane Fluttershy is on steroids
He's overly buff for a pony, has crazy eyes, and his wings are tiny (think of the wingboner meme and what steroids do to the privates)
 * I'm pretty sure this or something similar is canon. But what type of Steroids would exist in a world of magical ponies... Unicorn magic perhaps, or the type of herbal remedies Zecora makes?
 * It's testosterone, there's thousands of natural sources of it.

The "population of ponies back in the paleopony period" that was afflicted with true Cutie Pox are the ancestors of the ponies of Sunny Town.
That would explain why the town is so paranoid about cutie marks that. There were ponies long in their past that experienced Cutie Pox first-hand, so over time the story got twisted so that they thought it was a curse. The writers have given us a potential canon explanation for Story of the Blanks.

All the other statues are in the same situation as Discord.
In other words, all the stone statues around Discord were also stone ponies.