The male version of a Succubus is known as an Incubus and delivers the same role, though Incubi are a little more violent in nature - both are deadly creatures of the night and were born from medieval legends spawned from a period of history when the idea of chastity was sacred. The Succubus has become a staple of fiction ever since and has always retained her basic role as a seductress, though her exact nature and role has altered in every retelling. Like many other "night spirits" the succubus can now be explained thanks to the discovery of the medical condition known as Sleep Paralysis.