The Proud Family/WMG

The talking baby who seems to hate Oscar so much is actually The Brain, reincarnated.
They look similar. They sound similar. They act similar. Now, The Brain actually has a shot at world domination. When he grows up...
 * Oscar might be Pinky reincarnated, which would explain why the talking baby likes to torment him, because Pinky might be responsible for them becoming humans.

Wizard Kelly has no head.
The main reason he's so rich is that he won a huge settlement suit against the NBA after he lost his head in a tragic basketball accident.
 * We've seen the upper part (from the mouth up) of his head on occasion, though only from the back, or in silhouette. All this means is that he wears some kind of prosthesis; it's hideously unsettling or inadequate in appearance, perhaps made out of immobile wax.
 * No, the top of his head is a basketball with prosthetics.
 * Oscar did it with the Friends on the other side he is made of.
 * Actually, the Wizard's full face IS visible in the background in the episode "One In A Million" right before Oscar takes the shot for the million dollars

All natural disasters are caused by Al Roker.
He's a weatherman, he's a genie, and he's evil. Clearly, he's using his supernatural power to wreak havoc on the rest of us. The reason why the U.S is the country with the most tornados? Roker.
 * Hey, he's probably doing it to sabotage the main news teams! It all makes sense!

What are Proud Snacks really made of?
I say it's people. Any other guesses?
 * Evil. Pure evil.
 * They're made with voodoo. Oscar has friends on the other side.
 * Leftovers or crap.
 * He mixes up too much flavors that everyone likes. The result is an indescribably awful taste.

Stop me if you've heard this one before...
Many people have proposed that Oscar is in fact Dr. Facilier, but I have a different spin on the idea. Oscar is not aware of the fact that he is Facilier. Facilier is trapped inside of Oscar and manifests as a sort of voice inside his head, telling him to make bad decisions and sell his terrible snacks. The same things goes for Sugar Mama, although she knows she's Mama Odie. And Oscar's Butt Monkey status is punishment from his friends on the other side.

At least one of Dijonay's so-called "siblings" is actually her own kid.
I mean, just look at her.
 * That's not very nice.
 * And racist. Ever heard of this thing called genes? I don't remember seeing her parents on the show, but one can first and always assume they look like their parents and thus look like each other. Heck, haven't you ever heard of siblings who aren't twins looking like each other too?

Trudy cheats on Oscar.

 * And the evidence is?...
 * It's a WMG, it doesn't technically need evidence. However, the WMGs with the most evidence tend to be the most interesting and fun ones.

The Shape Shifting Girl was removed from the show.
Because she decided to become a criminal mastermind, and using her powers she could easily be whatever she wanted...her only mistake was finding her uncle Basil AKA Clayface but as it happened he wanted a protege...

Oscar isn't the only one who knows the talking baby.
The baby is a Jerkass enjoys tormenting other people he considers to be stupid. Oscar is his latest victim.