A succubus (plural succubi) is an evil demon stemming from Hebrew mythology. Like incubi, they seduce humans and mate with them to produce offspring. They are the female counterpart of an incubus and appear as part of the same race, except for being female. Succubi feed on nightmares and hate the day and light, and are similar to female vampires.
220px-Lilith (John Collier painting)

Lilith, in some traditions Adam's first wife and a succubus

Succubi are beautiful and desirable women, unlike their male counterparts, Incubi. Though Succubi do sometimes have bat-like wings or demonic features such as horns, a tail, hooves, and fangs. 

In medieval European lore, Succubi appeared to men in the night and seduced them into sexual encounters. Celibate monks seemed to be especially prone to such attacks, often blaming Succubi for their lustful thoughts or sexual dreams. Succubi could suck the life force of men, leaving them exhausted or even killing them.

According to the Zohar, the foundational work of literature commenting on the mystical aspects of the Torah, the first of four succubi was Lilith, depicted at the right. She was Adam's first wife but refused to return to the Garden of Eden and mated with the Archangel Samuel. Samuel had three other succubi for wives: Mahalath, Agrat Bat Mahlat, and Naamah.

See also