The Gorgon is a creature covered with impenetrable scales, hair of living snakes, hands of brass, sharp fangs and a beard. They were said to live in the west, near the ocean, and guard the entrance to the underworld.
A stone head or picture of a gorgon was often placed or drawn on temples and graves to avert evil, but also on the shields of soldiers. Such a head could also be found on the older coins of Athens.
Origins
In Greek mythology a gorgon is a monstrous feminine creature whose appearance would turn the beholder to stone. Later in history, there were three of them: Euryale ("far-roaming"), Sthenno ("forceful"), and Medusa ("ruler"), the latter being the only one of them who was mortal. They were the three daughters of Phorcys and Ceto.