evil spirit - a spirit tending to cause harm

incubus - a male demon believed to lie on sleeping persons and to have sexual intercourse with sleeping women

succuba, succubus - a female demon believed to have sexual intercourse with sleeping men

dibbuk, dybbuk - (Jewish folklore) a demon that enters the body of a living person and controls that body's behavior

disagreeable person, unpleasant person - a person who is not pleasant or agreeable

demoniac - someone who acts as if possessed by a demon

doer, actor, worker - a person who acts and gets things done; "he's a principal actor in this affair"; "when you want something done get a doer"; "he's a miracle worker"