Empusa

Empusa (plural Empousai) are servants of Hecate, goddess of witchcraft and crossroads. Aristophanes mocks her in The Frogs, where Dionysus is terrified to encounter one. Philostratus preserves the fullest account: Apollonius of Tyana exposed an Empusa posing as his student's bride, who confessed she was fattening him for consumption.

Her natural form is asymmetrical and unsettling — one leg is bronze, the other a donkey's leg (or sometimes a goat's). She has flaming hair and a hideous face. She transforms these features away when presenting as a beautiful woman.

Shape-shifts into a beautiful young woman to seduce and trap victims. Takes the forms of animals — especially dogs — for concealment. Feeds on blood and flesh. Flees only when her true name is spoken or when Hecate's mysteries are correctly invoked.