Medusa
Medusa a sea nymph, was one of three gorgon sisters, and the most beautiful. She was courted by Poseidon, and made love to him in a temple of Athena. Furious, Athena transformed Medusa into a monstrous chthonic beast with snakes instead of hair, whose frightening face could turn onlookers to stone. She was beheaded while sleeping by the hero Perseus, who thereafter used her head as a weapon until giving it to the goddess Athena to place on her shield.