 The monkey decides to defecate on the crab, and sticks his buttocks down the hole.The crab quickly shaves the monkey's bottom, which is why to this day monkeys have hairless bottoms and hair grows on crabs' claws.Similar stories involving a crab and a monkey, or a monkey and a toad, or other creatures seeking vengeance are found in China, Korea, and Mongolia, and among the Ainu.