Medusa, in Greek mythology, the most famous of the monster figures known as Gorgons. She was usually represented as a winged female creature having a head of hair consisting of snakes; unlike the Gorgons, she was sometimes represented as very beautiful. Medusa was the only Gorgon who was mortal; hence her slayer, Perseus, was able to kill her by cutting off her head. From the blood that spurted from her neck sprang Chrysaor and Pegasus, her two sons by Poseidon. The severed head, which had the power of turning into stone all who looked upon it, was given to Athena, who placed it in her shield; according to another account, Perseus buried it in the marketplace of Argos.
Heracles (Hercules) is said to have obtained a lock of Medusa’s hair (which possessed the same powers as the head) from Athena and given it to Sterope, the daughter of Cepheus, as a protection for the town of Tegea against attack; when exposed to view, the lock was supposed to bring on a storm, which put the enemy to flight.