Incubi, or male demons, then use the semen to impregnate human females, 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.According to other legends, the children of Lilith are called Lilin.
They also suck out a humans soul hence the name succubous.
While the book does not address why a human female impregnated with the semen of a human male would not produce regular human offspring, an explanation could be that the semen is altered before being transferred to the female host.
However in some lore, the child is born deformed because the conception was unnatural.
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 transportation of the substance could not be instantly transported to a female host, causing it to go cold.
A succubus/incubus appears almost entirely human, and it's very difficult to identify their supernatural true nature; they seem to live and age like humans do, and to be able to survive on a normal human diet.