Demon Spawn are summoned by the Necronomicon, whom need host bodies. Physically they are black skinned humanoid demons with sharp teeth and black hole-like eyes. Their bodies are extremely flexible which gives them remarkable maneuverability. Demon spawn are great climbers, and are stealthy, using the shadows.
They can negate one's immortality, turning you into a mortal. Are able to elongate their body parts, including their claws. If injured, the flesh repairs itself and can only be killed by supernaturally forged weapons. They are able to transform and mimic the shadows of other individuals.