The Erinyes (or the Furies) were goddesses of natural law, protecting blood ties in particular. They didn't like murder or rape, and punished offenders by tormenting them rather than striking them down dead. They bring justice, however can be appeased, becoming the Eumenides. Traditionally there are three - Tisiphone , Megaera, Alecto and are said to be the daughter of Nyx, one of the oldest female deities of the night/ darkness. Their symbols are the snake and blood.