In medieval legend, a succubus (plural succubi; from Latin succubare, "to lie under") is a female demon which comes to men, especially monks, in their dreams to seduce them and have sexual intercourse, drawing energy from the men to sustain themselves, often until the point of exhaustion or death. This legend was an explanation for the phenomena of wet dreams and sleep paralysis. From mythology and fantasy, Lilith and the Lilin (Jewish), Lilitu (Sumerian) and Rusalka (Slavic) were succubi.

According to the Malleus Maleficarum, or "Witches' Hammer", succubi would collect semen from the men they slept with, which incubi would then use to impregnate women. Children so begotten were supposed to be more susceptible to the influence of demons.

From the 16th century, the carving of a succubus on the outside of an inn indicated that the establishment also operated as a brothel.

Succuba (plural succubæ) is the more correct form because the -us is masculine in Latin, but the former is more commonly found in modern English literature.

Succubi often feature in fantasy role-playing games. In Dungeons & Dragons succubi are numerous tanar'ri demons, many under the command of the Abyssal Lord Graz'zt . Succubi are featured prominently in the Planescape games, and in D&D the female child of a succubus and a human is traditionally called an "Alu-demon" and the male child a "Cambion". Also, the offspring of an alu-demon or cambion's union with a human is known as a tiefling. They are also frequently seen in the Castlevania video game series as enemies. Succubi are also featured in several Blizzard Entertainment games, such as Diablo and World of Warcraft. Another popular succubus is Morrigan Aensland from the Darkstalkers series, also appearing in many of other Capcom fighting games. Another succubus, Lilith, later made an appearance in Darkstalkers 3 - Jedah's Damnation.

See also

• Incubus, a male version of the demon.
• Interdimensional hypothesis
• Neuralger, a related but potentially less damaging demon.