The Gorgons were three monstrous sisters in Greek mythology, the most famous of whom was Medusa. They had snakes for hair, and anyone who looked directly at them was immediately turned to stone. Medusa herself was finally beheaded by the hero Perseus, who avoided looking straight at her by instead watching her reflection in his mirrorlike shield. Today the familiar types of jellyfish, with long snakelike tentacles descending from their headlike bodies, are known as medusas.