Incubus and Succubus
These two demons were quite prominent in medieval urban legends. The incubus is a male demon who, according to mythology, sneaked into women’s bedrooms in order to have sex with them while they were sleeping for various purposes. The succubus is his female counterpart. The symptoms of such a visit included waking dreams or sleep paralysis.
The church, well-known for providing explanations that shamed women, used the incubi as one of those explanations for their sexual sins.