Bloom County/WMG

Bloom County takes place in the same universe as Questionable Content.
The Banana Computer is The Eighties precursor to AnthroPCs. Talking penguins are well-known in Questionable Content but not native to North America; Opus is an immigrant in Bloom County canon. The other talking animals are either native to the Midwest and unlikely to travel to a smallish college town in western Massachusetts, or are Steve Dallas's hangover effects.

Opus is not a puffin. He's a penguin who is mildly allergic to dandelions.
He started out looking like a penguin when he first moved to Bloom County as Binkley's pet. (Admittedly, he thought he was a dog at first. The penguin/puffin mistake could be reasonable.) His mother (seen in silhouette during the Mary Kay Testing Labs arc) has a narrow beak. And Opus's nose only started growing after he'd lived in Bloom County for a while. It wasn't an Art Shift; it's the dandelions!

The weirdness surrounding the dandelions may also explain Rosebud and the jackabasselope puppies.

Milo's Grandfather was murdered.
In Loose Tails we see that he is a member of something called the Moose Lodge. After that, he began to suffer Brother Chuck Syndrome...

But this is completely explained. In Tales Too Ticklish to Tell, we see a man convicted of murdering the entire Moose Lodge. Milo's grandfather was a member of the Moose Lodge. Hence, Milo's grandfather was murdered.
 * That's... morbid. And brilliant.

Opus' beak is deformed because he learned to speak.
He can''t talk at first. Then he starts learning to talk, and his beak starts growing. The same thing for his Feather Fingers because he learned to play the tuba.

Opus's fingers are real fingers.
Birds have fingerbones just like humans do, but they are usually spread far apart to support the wings so those wings can stretch out to fly. Penguin/puffin wings are built differently that most bird wings -- they are designed for swimming, and thus they are more compact that most bird wings. Opus neither flies nor swims, so when he needed fingers, the bone structure was available.

The unexplained disappearances of characters in the Bloom-verse suggest mundane fates.
Bobbi, Alf, and Banana Jr. 6000 had canon reasons for leaving the strip. Likewise for Senator Bedfellow and Lola, who both later returned in Opus. And it was suggested in this very WMG that Major Bloom was probably murdered with the rest of the Moose Lodge.

The other disappeared characters, however, may have had more mundane fates, as happens in everyday life:
 * Yaz Pistachio went away to college.
 * Rabies got loose (or got bored) and ran off.
 * Blondie and Alphonso moved to other towns with their respective sets of parents.
 * Limekiller was arrested, and/or he ran off after his comments in the Meadow Party Election. Coming off as a sexist and a racist and calling a disabled person a cripple (as well as entirely ignoring the animal portion of the party, which made up half of the party).
 * Otis Oracle moved off to Lynchburg, Virginia, to join the Moral Majority. And when the main chapter fell, he possibly joined the Westburro Baptist Church.
 * Tess Turbo fell out of pop cultural relevance. And, given her thoughts during her first appearance, went on to have a career revival after a successful autobiography, this time in the more soulful stuff.
 * Milo went off in search of America (think about it: he was on a bus in the very last Outland comic).
 * In between Outland and Opus (or even between Bloom County and Outland), child prodigy Oliver was accepted to some prestigious academy for the gifted.
 * Around the time of the Major's death, Bess Bloom also died. The town let Milo keep the boarding house instead of sending him to a foster home, since Milo seemed to be running the boarding house later on.
 * Pops Paplov and Ruby Tucker moved out, possibly together.
 * Lola Limekiller left to find her son.

Milo is Jason Fox.
They are both skinny, short, nerds who wear glasses. They're both from popular Newspaper Comics, and they both have blond hair. Compare this with this.
 * Also, Oliver is Marcus. Not only are they both black nerds, they have the same last name: Jones.
 * The reason Milo was on a bus in the 2nd-to-last Outland strip was because he was moving to Illinois, setting up Foxtrot.
 * And the Banana Jr. 6000 was an early version of the iFruit.