Amanojaku

a statue of an Amanojaku

Amanojaku is a malevolent kind of legendary creature in Japanese folklore. It is usually depicted as a small demon or lesser oni and is thought to be able to provoke a person's darkest desires and thus instigate them into committing wicked deeds: in many ways this makes it a "cousin" of the Western concept of a devil that sits on people's shoulders and tells them to do evil (sometimes referred to as an imp or devil)

Urikohime

An Amanojaku acted as the antagonist of the fairytale Urikohime, in which a girl miraculously born from a melon is doted upon by an elderly couple. They shelter her from the outside world, and she naively lets a Amanojaku inside one day, where it kidnaps or devours her, and sometimes impersonates her by wearing her flayed skin.