The Erinyes, also known as the Furies, the Eumenides, and the Dirae, are Greek goddesses of vengeance. “Erinyes” means “the angry ones”, while Eumenides means “Kindly Ones” or “Gracious Ones”. The Erinyes are commonly said to chase down perjurers, oath-breakers, those who commit crimes against the gods, and kin-slayers.
There is no definite number of Erinyes, so any number could be pictured. In art, the Furies tend to be shown with wings of some kind and snakes in their hair and around their arms and waist. Otherwise the Furies are entirely human women. They dressed either as hunter-maidens in short tunics and boots or in the long black robes of mourners. One source says their eyes dripped blood.
Original Greek mythology did not name specific Erinyes. It was not until Vergil that three Erinyes were recognized with names: Tisiphone (“avenging murder”), Alekto (“unceasing”), and Megaera (“ungrudging”).
The Erinyes are cthonic (meaning of the earth, therefore from Gaia) deities, born from the blood of Ouranos’ castrated genitalia. Another source also says the Erinyes were born from the primordial deity Nyx, meaning they also are primordial. Either way, these goddesses are older than the Olympians.
Ancient people feared to call the Erinyes by their proper name, so they used a euphemism, the Eumenides. This euphemism eased their fear and also was supposed to sooth the Erinyes and keep from drawing their attention.
The most powerful invocation of the Erinyes was that of a parent upon a child, because the Furies were born from a violent act of a child attacking the parent. The Erinyes could also be called down on a criminal by the victim in order to seek justice. The punishments of the Furies varied, from disease and illness to withered crops and dearth. The most severe punishment from the goddesses was a tormenting madness, but this was usually reserved for patricide/matricide. As servants of Hades and Persephone, the Erinyes lived in the underworld and would torture the souls of criminals in the lands of the damned.
In a play by Aeschelus, the Erinyes chased Orestes after he killed his mother Clytemnestra.
The only way to shake the Furies off your trail is to complete a ritual purification and an assigned task of atonement.
The only positive side I can think of for these goddesses is that of justice. The Furies enact justice for crimes even if human justice can’t be accomplished. In addition, the Furies tend to only punish people for actions that are almost universally acknowledged to be crimes, such as murder and oath-breaking. In that sense, they are somewhat like divine policemen. However, there isn’t much else about them that can be said to be good.
The goddesses were fairly thoroughly Dark. Although not all deities associated with the underworld are Dark gods, these live up to the association between Darkness and underworld. They torment not only humans’ bodies, but their souls after death as well, making these goddesses especially fearful.