In Western medieval legend, a succubus (plural succubi) or succuba (plural succubae) is a demon who takes the form of a beautiful woman to seduce men in dreams. They draw energy from the men to sustain themselves, until the point of exhaustion or death of the victim. From mythology and fantasy, Lilith and the Lilin (Jewish) and Lilitu (Sumerian) are, in redactive Christian fables (folktales not part of official Christian theology), considered succubi.

According to the Malleus Maleficarum, or "Witches' Hammer", published against the recommendation of the Catholic Church in 1487 and officially banned in 1490, succubi would collect seed from the men they were with, which incubi would then use to impregnate women thus explaining how demons could apparently sire children in spite of the traditional belief that demons were incapable of reproduction through generative or gestative means.

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

Hawaiian belief

The Hawaiian version of this myth is known as "Autumniessink". A mythological being that appears as a "beautiful young woman" and sneaks into mens tents at night and steals their innocense. It is said that the only way to stop this demon is to wear a loin cloth made of the Hawaiian "snowbush plant".

Middle Eastern belief

A Middle Eastern version of the succubus known as "um al duwayce" (أٌم الدويس) portrays this succubus as a beautiful, alluringly scented woman who wanders the desert on the hooves of a camel. This particular succubus is a judge of character and exacts revenge on those who commit adultery. She attempts to lure these men to have "adult content" at which time sharp razors within "adult content" slice "adult content" leaving him in agonizing pain. Having rendered the man helpless, she turns into her true form and proceeds to eat him alive.

Appearance

The appearance of succubi varies, but in general they are depicted as alluring women with unearthly beauty, often with demonic batlike wings, and large breasts; they also have other demonic features, such as horns and cloven feet. Occasionally they appear as an attractive woman in dreams that the victim cannot seem to get off their mind. They lure males and in some cases, the male has seemed to fall "in love" with her. Even out of the dream she will not leave his mind. She will remain there slowly draining energy from him until death by exhaustion. Other sources say the demon will steal the male's soul.

The word "succubus" comes from an alteration of the Late Latin succuba meaning "strumpet". The word itself is derived from the Latin prefix "sub-" which means "below, underneath", and the verb "cubo" which means "I lie". So a succubus is someone who lies under another person, whereas an incubus (Latin "in-" in this case stands for "on top") is someone who lies on top of another person.

Mare was also a term for the sighing, suffocative panting, or an intercepted utterance, with a sense of pressure across the chest, which occurs during sleep. These symptoms were also thought to be an incubus (or succubus), an evil preternatural being, causing nightmares and/or nocturnal emissions. This phenomenon is now thought to be an experience of sleep paralysis.