7. Sid from Toy Story became a garbageman for a very special purpose
Sadistic toy-torturing happy child Sid seemed to have been scared out of the series for good after the first movie, but he made a brief in Toy Story 3. If you pay attention towards the end of the movie, you can spot a garbageman rockin' out with what seems to be a familiar skull shirt. From the faded color of his angsty garment to his awful goatee, all the clues point to an appropriately-aged up Sid.
So why did Sid grow up to become a garbageman? You know, besides getting to work outside with great pay and dope bennies. As a real-life garbageman points out, you find a ton of discarded toys in the trash. And in the world of Toy Story, Sid is the only human that knows toys are alive. With that kind of knowledge in mind, could anyone stand by and watch as thousands of living things are murdered each day? No. Sid became a garbageman to save toys from being thrown away.
This theory gained a lot of popularity because it's sweet, and we like to think that everyone is redeemable. Imagining Sid dedicating his life to saving toys -- even though he'll never be thanked and no one will ever know what he's done -- gives us a good feeling inside. There's probably a heartwarming movie in the story of a troubled teen who finds redemption in the neighorhood dirty work.
Too bad that whole theory is a crock. All you have to do is watch the rest of that scene, and you'll see that Sid hasn't changed.
Despite knowing what he knows, Sid still crucifies errant stuffed animals he finds along his route. Sid is not actually saving these toys -- he's collecting them to be thrown away and to die in the incinerator. If he's changed at all, it's for the worse. Sid is a toy serial killer.
Part of the blame no doubt belongs on Woody and his motley gang of frankentoys.
If you were traumatized by a mutant baby spider as a child, you'd probably want all toys to die in a fire, too. In a way, Woody's plan to freak out Sid inadvertently caused the excruciating torture and death of hundreds of toys years down the line. I guess we know who poisoned the water hole, after all.
6. The hidden murder in The Emperor's New Groove
The Emperor's New Groove is one of Disney's funniest and most lighthearted animated features, thanks mostly to the fact that it stars a talking llama (and Patrick Warburton). But if you're paying attention, you can catch a glimpse of the movie's dark side.
A little bit after Kuzco is first llamafied, he's walking through a spooky forest on his own. That's when he sees an unlucky fly get caught in a spider's web.
That animators created a fully realized creature only to kill it seconds later is messed up enough, but then they had to go and make it yell for help. That's really strange, because no other animal in the movie talks -- only those who were once humans. One Reddit user theorizes that this fly was once human, and what we're witnessing is the final moments of a poor transmogriphied man or woman.
Maybe Kuzco can understand animal speech? But that wouldn't explain why he can't talk to squirrels without interpretation from Kronk.
It seems likely that Kuzco wasn't the first one to be turned into an animal by the evil Yzma. There are all sorts of transformative potions featured in the finale, and if there are elixirs for whales and parrots, there's probably something that would make you into a fly. Yzma more than likely punished one of her underlings by dosing them with just such a potion, leaving them to rough it in the jungle. As pointed out by astute commenter Todd, Yzma originally plans to turn Kuzco into a flea, which is basically a fly that likes to eat blood instead of poop.
This revelation is made all the more disturbing by the fact that we actually hear the spider talk, too. Listen closely after it chows down on the fly, and you can catch the spider say "Too late!" The implication being that the spider was once human also; this isn't just a murder, it's cannibalism. Boom, baby!