An incubus is a demon in male form who, according to mythological and legendary traditions, lies upon sleeping women in order to engage in sexual activity with them. Belief in and the debate around incubi began early in the Christian tradition. St Augustine of Hippo wrote of the demon, going so far as to state there are “too many accounts to deny.” Both Augustine and King James stated in their writings that the neither the incubus or succubus could produce demon seed themselves. That is to say that they could not beget offspring of their own being, but instead steal seed from humans, dead or alive, and impregnate living women. This was done in various ways, including the theft of semen from a living or recently deceased corpse. The corpse would have to be fresh, as the semen would go cold and be unusable. A way for the incubus to get around this problem would be to inhabit the corpse itself, rise from the dead, to lie with its female victims, putting a child in their womb.
It is said that one can identify an incubus by its unusually large and cold penis. The children of the incubus/succubus are cambion, the unnatural halfbreed of the earthly and unearthly. While human, made with human seed, they are bestowed with supernatural powers. Merlin was said to be a cambion, the reason behind his great magical abilities. It was not unheard of for folks in the community to be accused of being cambion, especially if the pregnancy itself was unexplained. Within the Maleus Malificarum, the Hammer of Witches, there are instructions to combat the effects of an incubus on its victims. Exorcism is one of the five ways stated, the others being Sacremental Confession, the Sign of the Cross, recital of the Angelic Salutation, or the moving of the afflicted to a different location. However, the franciscan friar Ludovico Maria Sinistrari wrote that the incubi “do not obey exorcists, have no dread of exorcisms, show no reverence for holy things, at the approach of which they are not in the least overawed.” It would appear that to some, we are defenseless against the spirit.
The incubus, along with the succubus, are an ancient evil, seen in various cultures globally. The alp of German mythology is something akin to a vampiric incubus. The trauco in provincial Chilean folklore is a hideous deformed creature of small stature who lulls nubile young women to seduces them in a dream state. A lidérc is a satanic lover who flies at night in Hungarian legend. Brazil, South Africa and Sweden all have their own variations, as well as the near and far east. The demonic lover is a spirit that has haunted man and woman alike as far back as our written stories. It bares a resemblance to the more recently understood phenomena of sleep paralysis, especially the succubus, with the hag laying atop the male victim. Many point to this as an example of early man attempting to explain away sleep paralysis and nightmares.