According to the Malleus Maleficarum, or Witches' Hammer, written by Heinrich Kramer (Institoris) in 1486, succubi collect semen from men they seduce. Incubi, or male demons, then use the semen to impregnate human females,[12] thus explaining how demons could apparently sire children, despite the traditional belief that they were incapable of reproduction. Children so begotten—cambions—were supposed to be those that were born deformed, or more susceptible to supernatural influences.[13]

King James in his dissertation titled Dæmonologie refutes the possibility for angelic entities to reproduce and instead offered a suggestion that a devil would carry out two methods of impregnating women - the first, to steal the sperm out of a dead man and deliver it into a woman. If a demon could extract the semen quickly, the substance could not be instantly transported to a female host, causing it to go cold. This explains his view that succubi and incubi were the same demonic entity, only to be described differently based on the tormented sexes being conversed with. The second method was the idea that a dead body could be possessed by a devil, causing it to rise and have sexual relations with others. However, no mention has been found of a female corpse being possessed to elicit sex from men.[14]