In Greek mythology Medusa was a monster, a Gorgon, generally described as having the face of a hideous human female with living venomous snakes in place of hair. Gazing directly into her eyes would turn onlookers to stone.

Famous is the story about Medusa beheaded by the hero Perseus, who thereafter used her head, which retained its ability to turn onlookers to stone, as a weapon until he gave it to the goddess Athena to place on her shield.

Monster girl Medusas exist too as a type of Role > Snake Person, having in common the same appearance: upper body of a human woman and the lower body of a snake. They differ from other snake people in that they possess the ability to cause the body of whomever they make eye contact with to harden like stone.