In medieval legend, a succubus (plural succubi; from Latin succuba; "prostitute") is a female demon that seduces men (especially monks) in dreams to have sexual intercourse.
They draw energy from the men to sustain themselves, often until the point of exhaustion or death of the victim. 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.
Honoré de Balzac wrote a short story The Succubus  concerning a 1271 trial of a she-devil succubus in the guise of a woman, who amongst other things could use her hair to entangle victims.
From the 16th century, the carving of a succubus on the outside of an inn indicated that the establishment also operated as a brothel.
The appearance of succubi varies just about as much as that of demons in general; there is no single definitive depiction. However, they are almost universally depicted as alluring women with unearthly beauty, often with demonic batlike wings; occasionally, they will be given other demonic features (horns, a tail with a spaded tip, snakelike eyes, hooves, etc). Occasionally they appear simply 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.
In modern times
To this day the blame of nocturnal emissions and other sexual occurrences or mysteries are, in some cultures and circles, blamed on a demon of sins such as a succubus.
Experiences of apparent supernatural visitations at night can sometimes occur as effects of hypnagogia.
The succubus is a popular figure in modern fantasy fiction.
Mare was also a term for the sighing, suffocative panting, or an intercepted utterance, with a sense of pressure across the chest, which occurring during sleep. These symptoms were also thought to be an incubus (or succubus), a evil preternatural being causing nightmares and/or nocturnal emissions.
Succubi are often featured in fantasy fiction and role-playing games, and often shown with batlike wings and bikini clad.
Succubi are often very prominent in the sexual aspects of fantasy fandoms and paraphilia.
- The Marvel Comics character “Satana” is a succubus.
- The character Drusilla in the online comic strip “Pibgorn” is a succubus in mufti.
- Castlevania The succubus is a popular, recurring enemy in the series, undergoing many different appearances and different attack styles. In "Symphony of the Night" and "Lament of Innocence", the Succubus Scarlet is one of the main characters as well as one of Dracula's attendants. It could be argued that she and Dracula's compatriot Carmilla have interchangeable roles in the games.
- Phantasy Star The succubus appears in a dream battle sequence early in the game.
- Ragnarok Online The succubus is a powerful monster in the dungeon, Geffenia.
- City of Heroes/City of Villains Succubi are one of several types of demons bound in the service of the mystical Circle of Thorns, who specialize in confusing players into attacking their teammates.
- Darkstalkers The character Morrigan Aensland and her sister Lilith Aensland are Succubi.
- Diablo II: Lord of Destruction The succubus  can be found in great quantity in Act V; their appearance has been controversial because of their scantly clad bodies and constant moaning.
- World of Warcraft The warlock class is able to obtain a succubus as a pet at level 20, which has the abilities to make herself invisible and "charm" (sleep effect) an opponent for a short amount of time.
- The succubus is a type of tanar'ri in the Dungeons & Dragons fantasy role-playing game.
- The CRPG Planescape: Torment features “Fall-From-Grace”, or simply “Grace”, as a chaste Succubus priestess that can join the player's party. She is depicted as a beautiful blond woman with batwings. She is the only healer in the game and can serve as a potential romantic interest for the player, albeit only mildly so. Fall-From-Grace is voiced by Jennifer Hale.
- In Star Ocean 3, a Succubus appears in Level 2 at the Maze of Tribulations to fight the party. Its attacks include Charm Person, which causes Chaos (Status ailment) on any male party member.
- Succubus is a boss in the video game Devil May Cry 3. Dantes Awakening, where the creature is a witch and an energetic vampire called Nevan, who can control electricity and uses bats as a protection from Dante's attacks.
-  Charles Williams's 1937 novel Descent into Hell features an academic who consciously rejects the potential affections of a real woman in favor of a physically identical but perfectly obedient and pliable succubus
-  In Orson Scott Card's novel Treasure Box, a witch conjures a succubus that represents the dreams and desires of the protagonist to convince him to open a mysterious box
-  Succubi and incubi are both referenced by the Reverend Hale in Arthur Miller's classic play The Crucible
-  A succubus-like creature called a “neuralger” appears in Terry Patchett's Discworld novel Eric
- O Brother Where Art Thou, a 2000 film starring George Clooney in which he calls his wife a succubus
- White Skin A university student falls in love with a Succubus 
- Silent Hill 4: The Room, A female ghost takes the form of a creature that drains the health of the main character and can entangle him to keep him from running away.
- Charmed, a popular TV series, features a succubus during the season two episode "She's a Man, Baby, a Man!". Prue becomes a man in order to attract the Succubus who is murdering local men. She is portrayed as a beautiful woman with a snake-like tongue.
- Power Rangers: Mystic Force, the 14th season of the popular TV show had an episode called "Soul Specter" which had a Succubus named Gnatu.
- South Park The boys stop Chef from marrying a Succubus and defeat the demon singing the “The Morning After” (Maureen McGovern’ song, love theme for The Poseidon Adventure) backwards.
- The now-defunct series She-Wolf of London featured a succubus, causing immediate and extreme aging in her victims.