AEGIS

[Greek] A protective device that was originally associated with Zeus, but also, and later solely, with Athena. It is variously considered to be a bright-edged thundercloud (because when Zeus used it lightning flashed and thunder sounded) fashioned by Hephaestus, or the skin of the divine goat Amaltheia. It is represented as a sort of cloak, sometimes covered with scales and fringed with serpents, and with the head of Medusa fastened in the middle. The Aegis could also serve as a shield and in that fashion Athena wears it upon her breastplate.