Hihi (狒々 or 比々, lit. "baboon") are large yōkai who live in the mountains and possess superhuman strength. They are known to carry off human women, and some villages would even sacrifice women to them to ensure the safety of the rest of the villagers. Because they are able to change into a great ape, it is believed that these yōkai were once aged monkeys. Their eyes are the only vulnerable part of their bodies, and dogs are their mortal enemy. They are covered with a thick coat of fur that acts much like an impenetrable shell.