In Greek mythology, the Gorgons ("terrible" or, according to some, "loud-roaring") were vicious female monsters with sharp fangs and hair of living, venomous snakes.

They are sometimes depicted as having wings of gold, brazen claws, and the tusks of boars. According to the myths, seeing the face of a Gorgon turned the viewer to stone. Homer speaks of only one Gorgon, whose head is represented in the Iliad as fixed in the centre of the aegis of Zeus. In the Odyssey, she is a monster of the underworld. Hesiod increases the number of Gorgons to three -- Stheno (the mighty), Euryale (the far-springer) and Medusa (the queen), and makes them the daughters of the sea-god Phorcys and of Keto. Their home is on the farthest side of the western ocean; according to later authorities, in Libya. The Attic tradition, reproduced in Euripides, regarded the Gorgon as a monster, produced by Gaia to aid her sons the giants against the gods and slain by Athena.

According to Ovid (Metamorphoses), Medusa alone had serpents in her hair, and this was due to Minerva (Athena) cursing her. Medusa had copulated with Neptune (Poseidon), who was aroused by the golden color of Medusa's hair, in a temple of Minerva. Minerva therefore changed the enticing golden locks into serpents. Aeschylus says that the three Gorgons had only one tooth and one eye between them (see also the Graeae), which they had to swap between themselves.

Medusa was the only one of the three who was mortal; hence Perseus was able to kill her by cutting off her head while looking at her in the reflection in a mirrored shield he got from the Graeae. Some authors say that Perseus was armed with a scythe by Mercury (Hermes) and a mirror by Minerva. Whether the mirrored shield or the scythe, these weapons allowed him to defeat Medusa easily. From the blood that spurted from her neck sprang Chrysaor and Pegasus, her two sons by Poseidon. He gave the head, which had the power of turning into stone all who looked upon it, to Athena, who placed it in her shield; according to another account, Perseus buried it in the marketplace of Argos.

A gorgoneion (or stone head, engraving or drawing of a Gorgon face, often with snakes protruding wildly and tongue sticking out between the fangs) was frequently placed on doors, walls, coins, shields, breastplates, and tombstones in the hopes of warding off evil. In this regard the gorgoneion are similar to the sometimes grotesque faces on Chinese soldiers’ shields, also used generally as an amulet, a protection against the evil eye.

In Greek mythology, blood taken from the right side of a Gorgon could bring the dead back to life, yet blood taken from the left side was an instantly fatal poison. Athena gave a vial of the healing blood to Asclepius, which ultimately brought about his demise.

Heracles 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.

According to the later idea of Medusa as a beautiful maiden, whose hair had been changed into snakes by Athena, the head was represented in works of art with a wonderfully handsome face, wrapped in the calm repose of death.

This article incorporates text from the public domain 1911 Encyclopædia Britannica.

Additional material has been added from the 1824 Lempriere's Dictionary