Water, Water Every Hare (1952)

Bugs Bunny is too sound a sleeper to notice that a sudden rainstorm has flooded his rabbit hole and sent his mattress, with him on it, floating downstream toward a castle with helpful neon signs that say "Evil Scientist" and "Boo." Said Evil Scientist needs a brain for his mechanical monster, and when he sees Bugs Bunny floating by, decides a rabbit's brain is as good as any other. Bugs Bunny awakens to the horror of reposing mummies, an Evil Scientist with a huge, green head and an enormous robot waiting for its brain. Bugs tries to escape, but the scientist sends Rudolph after him. Rudolph is an unlikely beast covered with orange fur; it wears sneakers, but why not? Who says monsters don't have sensitive feet? Bugs poses as a chatty hairdresser, uses vanishing fluid on himself, and pours reducing fluid on the beast to thwart him. But Bugs's only weapon against the Evil Scientist will be a broken bottle of ether. Will it be enough?