Furies [r]: From Greek mythology, they were spirits of blood vengeance who avenge violence against kin, with a particular focus when violence is by children against their parents. In the Theogony by Hesiod, they were born from drops of blood from the severed genitals of Ouranos. In Eumenides by Euripides, they tormented Orestes for killing his mother, Clytemnestra. [e]