The Redjac is a non-corporeal parasitic lifeform that existed for centuries by journeying from planet to planet and feeding on the pain and fear he caused by committing serial murders. It requires a host to inhabit in order to commit its crimes. It had many abilities, and can possess others and objects, even spaceship size ones.
One such entity seems to have existed on Earth from at least the 19th to the 22nd century.
It shares some characteristics with the Beta XII-A entity.