The incubus is a nocturnal demon whose traditional role involves entering bedrooms and troubling sleepers with erotic or terrifying dreams. For poets, it can embody the pressure of unwanted desire, bodily vulnerability, and the frightening uncertainty between sleep and waking. Its presence may be rendered as weight on the chest, a shadow at the bedstead, or a voice that seems to arise from within the dreamer. The incubus is useful in Gothic poems where intimacy becomes invasion.

The incubus is a male supernatural being in European medieval and later folklore said to visit or oppress sleepers, often with explicitly sexual associations. Historical accounts intersect with religious beliefs, demonology, nightmares, and experiences now sometimes interpreted through sleep paralysis. Literary uses may explore fear, desire, repression, vulnerability, or the blurred boundary between dream and waking. Students should distinguish the folklore figure from modern fictional adaptations. Compare succubus, mare, nightmare, sleep paralysis, demonology, dream vision, temptation, nocturnal visitation, and supernatural oppression.