Shadow Demon

Shadow demons resemble standard shadows with wings. They are
the incorporeal form of a demon trapped in the form of a shadow as
punishment for some wrongdoing. If anything can release a demon
trapped in shadow form, only the dukes, princes, and lords of the Abyss
know such secrets. As a result of their new form, shadow demons are
malign and evil, destroying all life they encounter.
A shadow demon lurks in dark places, waiting for its prey to pass
nearby. Often before leaping to attack, it uses its deeper darkness to
gain the advantage. It then leaps from the shadows and attacks with its
incorporeal attacks.

Shadow Demon

Out of the Darkness and Into the Light ObsidianBlackbird