Different Demons

Incubus Demons
The Incubus is believed to be a demon that takes the form of a male that preys upon women while they sleep. The Incubus demon is believed to seek out women in order to father children. Merlin the magician was said to have been fathered by an Incubus demon. "Relations" with an Incubus demon is believed in mythology to cause sickness or even death.

Succubus Demons
The Succubus demon is the female counterpart to an Incubus. They are believed to prey on men in their sleep, seducing them through their dreams. The succubus is said to feed off of the energy drained from the male victims. Mythology states that a man targeted by a Succubus is often drained to the point of exhaustion or death.

Demonic possession
Demonic possession is a common belief involving demons. Possession involves the act of a demon inhabiting the body of a mortal, living thing.