Gorgon

In the Greek world, a Gorgon is a being that refers to any of the three sisters who had hair made of live and poisonous snakes, and a body with snake features, and petrifying eyes, daughters of Phorcys and Ceto.

The Gorgons were Stheno, Euryale and Medusa killed by the demigod and the hero Perseus.

Reference
Secrets of the Ancient World the guide used by game masters of the Hercules & Xena Roleplaying Game by West End Games.