Like their children, the Cambions, an Incubus always seems supernaturally attractive and charming. Their true forms consist of a large and serpentine demonic creature with skeletal phantom limbs that possess qualities of a bird, and their underbellies are constantly bathed in the blood of the victims they have taken over the ages, with their backs bearing striped fur But some people believe that when the Incubi slept with another male he would absorb his seed and use it as his own. Many believe that incubi are bisexual but that would strictly contradict their purpose of impregnation. They would then become incubi and use that semen to impregnate women. For example, they would become succubi whenever they required semen, their life source. It is also generally believed that incubus and succubus are actually the same demon, able to swap genders at specific points. Unless the Incubus slept with a succubus then the succubi would give birth to a new incubi or succubi. These human/incubi or succubi hybrid is called a Cambion. When they do, they will obtain supernatural abilities and can become extremely persuasive. The child is taken to Hell to be trained and raised as a member of their race. These births always result in either a pureblood Succubus or Incubus being born, and always kill the mother.

Incubi, unlike Succubi, are able to reproduce with females.

When a human has intercourse with a succubi/incubi over long amounts of time (say a month) they will start feeling a need for more sex with the incubi/succubi or go insane from how much life force they have lost.

They appear to know a myriad of information on topics of politics, theology of various religious, and demonology of the Judeo-Christian faiths. Incubi are often incredibly handsome, slim, and athletic men, cultured and highly intelligent. Moreover, the Asmodai consisted of both incubi and succubi, the latter of which were a lesser species of the Lilim, the first and strongest of the succubi that came into existence when Lilith mated with Samael. It is said that the incubi were also known as Asmodai which are considered a second horde of demons that were birthed from Lilith after mating with Asmodeus. The origins of the incubus are unknown, though it is more than likely that they originated from Lilith or one of her sisters. However, whereas Succubi target men (and often have an easier job), Incubi target women. They possess many of the abilities of the succubus, including their ability to take vessels and their supernatural ability to seduce.

Incubus dreams