The furies are three goddesses of vengeance from Roman mythology: Tisiphone (avenger of murder), Megaera (the jealous) and Alecto (constant anger). They were also known as the Daughters of the Night or the Erinyes (Greek mythology).
Horrible to look at, the Furies had snakes for hair and blood dripping from their eyes. Sometimes they were depicted as having wings of a bat or bird and the body of a dog.
Without mercy, the Furies would punish all crime including the breaking of rules considering all aspects of society. The wrath of the Furies manifested itself in a number of ways. The most severe of these was the tormenting madness inflected upon a patricide or matricide. Murderers might suffer illness or disease, and a nation harbouring such a criminal could suffer death, and with it hunger and disease.