Serpent seed
The doctrine of the serpent seed, also known as the dual-seed or the two-seedline doctrine, is a controversial belief in some fringe Christian or other Abrahamic religious movements that interprets the Biblical account of the fall of man as follows: the Serpent mated with Eve in the Garden of Eden, and the offspring of their union was Cain. Thus, adherents believe this event resulted in the creation of two races of people: the wicked descendants of the Serpent who were destined for damnation, and the righteous descendants of Adam who were destined to have eternal life.