Nightmare demon was the name of a near-mythical species from the planet of Droxine. They were small-sized primates with two tails, suction cup-tipped fingers and a bare head that resembled the Human skull. Nightmare demons had strong telepathic abilities that allowed them to drive other beings mad with nightmarish hallucinations. While they were believed to have been exterminated some time before the Clone Wars, some nightmare demons had survived the slaughter and fallen under Imperial control. In 3 ABY, a surviving demon named Reist attempted to murder the Rebel hero Luke Skywalker, only to be slain himself.