In Greek mythology, Medusa was originally a beautiful woman but was cursed and transformed into a monster with snakes for hair who could turn anyone who looked at her to stone. She was one of three Gorgon sisters along with Stheno and Euryale. There are different accounts for why Medusa was cursed, either because she engaged in a sexual act with the god Poseidon or because she married him after being told it was forbidden.