Gorgons

In Greek mythology, a Gorgon is a female creature. The name derives from the ancient Greek word gorgós, which means "dreadful". The term commonly refers to any of three sisters who had hair made of living, venomous snakes. They turned those who beheld them to stone. Traditionally, while two of the Gorgons were immortal, Stheno and Euryale, their sister Medusa was not, and she was slain by Perseus. The concept of the Gorgon is at least as old in classical Greek mythology as Perseus and Zeus. Gorgons were a popular image in Greek mythology, images of the Gorgons were put on objects and buildings for protection.

One of the earliest representations on coins is on an electrum stater from Parium. Going even further back, there is a similar image from the Knossos palace, dating to the fifteenth century BC.

See----->http://psjfactoids.blogspot.ca/2017/01/medusa.html