In Japanese mythology, a futakuchi-onna is woman transformed into a monster (yōkai) who has two mouths – their usual one on her face and the second one on the back of the head beneath the hair. These women would rarely eat, and to offset the lack of food the second mouth mysteriously appeared. The woman's hair moved and helped the second mother to the woman's meals. The second mouth would also mumble venomous obscenities to the woman, and if it wasn't fed, it would shriek and cause the woman tremendous pain
The futakuchi-onna belongs to a class of stories where women are afflicted with a curse or supernatural disease that transforms them into yōkai.
