Medusa

In the stories of the Greek heroes, Medusa was one of the Gorgon sisters whose hideous, snaky-haired head, the hero Perseus severed using a mirror given him by the gods so he wouldn't have to face her. Had he looked at her face, Medusa would have turned him to stone. Even after he had decapitated Medusa, Perseus couldn't look at her because her head retained its petrifying power.