WMG / Dumbo

The Pink Elephants Are Poltergeists
Normally, they are shy, nomadic spirits that roam the lands, usually keeping to themselves, unless they come across a person who is too mentally unsound (i.e. drunk) to strongly react to them, and thus begin their fun. While these creatures are shapeshifters, they have an odd preference for the form of pink-colored Pachyderms.

The Pink Elephants were Witches, and that was a barrier Dumbo and Timothy stumbled into.
Similar to poltergeists, Witches target (and often kill) people in despair. Don't try to tell me that was just alcohol they drank, and LSD's effects were only discovered in 1943 (two years after this movie took place). Fortunately our two heroes got out in time.
  • They may have been the Witch form of an elephant that wished, on some primitive level, to get out of the circus. The Dog Witch, Uhrmann, possibly indicates that Incubators also experimented on animals.

The kid who taunts Dumbo was teased for his own ears.
There's really nothing in the film to support this except a case of Fridge Brilliance; imagine you're a funny-looking kid with big ears, and all your friends tease you about it — not exactly a case of All of the Other Reindeer, as they still hang out with you, but they never miss a chance to take a shot at you for it. Your ears reach "meme" status among your peers, and they make a running gag out of teasing you for your big ears. Then, you have the good fortune of seeing an elephant with HUGE ears. You immediately pick up on a chance to divert attention from you, and you point out the ears of the elephant. Some of the insults he uses might even be some that he heard from his friends. Now, whenever the other kids say "you have big ears", you can say "at least they're not as big as that one elephant's". The joke loses its humor, and dies out, and you're free of ridicule. At least until someone decides to ask if you can fly as well.

That wasn't champagne the clowns were drinking.
So let me get this straight. A not even full bottle of champagne (around 12% alcohol by volume) gets diluted by an entire tub full of water, and a mere couple of gulps of this mixture is consumed by a creature with the mass of a baby elephant (probably around 260 lbs). And he almost immediately goes into what appear to be the final stages of delirium tremens. No freaking way. Those clowns had to be knocking back something a lot stronger than that. That stuff was spiked with LSD or mescaline or something.
  • Absinthe, perhaps? I've heard it be called the strongest drink there is. That could account for still being fairly strong even after dilution.
    • The water did turn a greenish color, which would fit. And while it's since been debunked, many have claimed over the years that absinthe causes hallucinations. Absinthe isn't fizzy, though, and the bottle looks much more like a champagne bottle.
  • Alternatively, maybe it wasn't just water in that tub... I can see an unethical circus sedating the animals to make them easier to manage.
    • Perhaps that tub of water was intended for Dumbo's mom, to keep her docile? Seems they'd need something pretty strong to keep a "mad" elephant under control.
      • Probably not a great idea, since it seems to cause terrifying hallucinations. Not the sort of thing to give an animal who is considered dangerous.
      • Maybe the sedative only causes hallucinations when it reacts with alcohol, otherwise it just makes the animals drowsy?

The stork that delivered Dumbo was a replacement stork

The original stork that was supposed to deliver Dumbo to the circus drank on the job one too many times and lost the elephant. When catching up to the rest of the flying V of storks, it got in trouble for losing the baby (and replacing it with Bugs Bunny), Long story short, the original stork was fired and a newbie stork was tasked to deliver a baby elephant to a moving train.

Dumbo is a hybrid elephant
The real Jumbo was an African elephant. Mrs. Jumbo and the other elephants are clearly Asian elephants. African elephants have much larger ears in relation to their (much larger) body size than Asian elephants, which have tiny ears (and are smaller to begin with). Clearly, Dumbo mostly takes after his mother, with the exception of his ears (which he'll probably mostly grow into).

This also explains why the other elephants are so damn scandalized when Dumbo's ears first unfurl.

  • And they're even larger than normal African elephant ears because he's a hybrid. Some hybrid animals have features that don't appear in either parent. Ligers, for instance, are much bigger than lions or tigers because of some weird gene stuff.
    • Unlike lions and tigers, the genetic differences between African and Asian elephants are too big to allow successful interbreeding.
The Elephants really are made of rubber.
One of the clowns makes this claim. It would certainly explain how the elephants manage to pull off all the stunts that they do.

Dumbo isn't really Mrs. Jumbo's son.
The stork made a mistake.

The Storks are a part of an adoption service.
Animals can still reproduce normally, but the ones in the circus are prohibited from doing so. The Storks, then, allow them to have babies anyway by bringing them babies to adopt.

Dumbo's life will be put in danger by someone trying to pull an Insurance Fraud.
After Dumbo becomes famous, one of the newspaper headlines featured in the movie states that his ears now have a million-dollar insurance. It's just a matter of time until someone decides that a million dollars is worth more than a flying elephant.

Dumbo's real father is Superman.
Or so this fanfic's author seems to believe. To quote the author, "If freakishly large ears were what granted you the ability to fly, every rabbit would be a helicopter. Other forces are obviously behind little Dumbo's ability to fly."