Medusa (Clash of the Titans)

Medusa is a Gorgon, a monsterous humanoid in the appearance of a human woman, but with real live snakes for hair, and a gaze of her eyes that can turn who looks into them into stone.

Background
Medusa was once a human priestess, who was punished by the Greek Goddess Athena, for having an affair (Not by choice) with Poseidon, The God of The Oceans.

She was turned by Athena, into the Gorgan she became to be, and was banished in a secluded area, away from society.