In Greek Mythology, the Graeae were three sisters who shared one eye and one tooth among themselves. They were the daughters of Phorcys and Ceto, and therefore the sisters of the Gorgons. They are connected with swans, and supposedly took the form of old, graying ladies. They were named Deino (Dread), Enyo (Horror) and Pemphredo (Alarm), and inhabited a cove near their sisters, the Gorgons.
Perseus stole their eye while they were passing it between themselves, and ransomed it in return for Medusa’s location. As consequence, Medusa was slain, and Chrysaor and Pegasus were created.