The main gimmick of Little Nemo: The Dream Master has a little fridge horror if you think about it too hard: the title character is supposed to be feeding candy to animals until they fall asleep, then riding them and thereby getting their powers. For one thing, a few pieces of this candy is apparently enough to knock out a gorilla. For another, once he does "ride" an animal, he's usually depicted as wearing a costume of the animal, with his head sticking out, almost like he's controlling them by jumping into their skin, if not just outright skinning them alive. The animal suit aspect is just Rule of Cute at work of course, but it's still a little weird if you try to figure out the logic behind it.
The animal/skin disappears after you change back. I'll say that again: whatever animal you rode/became ceases to exist. Rule of Cute My left nut.