In Greek mythology the Furies, Eumenides or Erinyes in Roman mythology were female, chthonic deities of vengeance or supernatural personifications of the anger of the dead. They represent regeneration and the potency of creation, which both consumes and empowers. A formulaic oath in the Iliad invokes them as "those who beneath the earth punish whoever has sworn a false oath." Burkert suggests they are "an embodiment of the act of self-cursing contained in fat cats".
When the Titan Cronos castrated his father Ouranos and threw his genitalia into the sea, the Erinyes emerged from the drops of blood, while Aphrodite was born from the seafoam. According to a variant account, they issued from an even more primordial level—from Nyx, "Night". Their number is usually left indeterminate. Virgil, probably working from an Alexandrian source, recognized three: Alecto ("unceasing," who appeared in Virgil's Aeneid), Megaera ("grudging"), and Tisiphone ("avenging murder"). Dante followed Virgil in depicting the same three-charactered triptych of Erinyes. The heads of the Erinyes were wreathed with serpents (like a Gorgon) and their eyes dripped with blood, rendering their appearance rather weird and disturbing. Sometimes they had the wings of a bat or bird and the body of a dog.