First conceived in ancient Greece and later adopted by ancient Rome, the ephélés (“one who leaps upon”) was a vampiric demon with hooked talons. Created when a person died before his time or by murder, the ephélés was a bringer of nightmares. At night it would sit on a sleeper’s chest, grabbing hold tightly with its hooks and sending forth bad dreams.

The ephélés was identified with the gods Artemis and Pan (Diana and Faunus in Roman times) as well as the satyrs, sirens, and Silvani. During the reign of Augustine, the ephélés were directly tied to the INCUBUS, SUCCUBUS, and the god Pan, who, apart from having dominion over flocks and shepherds, was also the giver of bad dreams.

Source: Hillman, Pan and the Nightmare, 97; Hufford, Terror That Comes in the Night, 131, 229; Rose, Handbook of Greek Mythology, 62; Royal Anthropological Institute, Man, 134