The term 'Underworld Goddess' refers to two different deities from Greek mythology. The first is Hel, the ruler of the underworld in Norse mythology. She was the daughter of Loki and was often depicted as a half-dead woman with a gloomy disposition. The second is Hecate, the Greek goddess of witchcraft, necromancy, and the underworld. She was associated with crossroads, entrance-ways, and the moon, and was often depicted with three heads or three bodies.