Demons (Somebody's Watching Me)

a variety of Demons act as the antagonists of the famous music video, "Somebody's Watching Me" by Rockwell, the song itself being a tribute to many horror themes and while the lyrics and video suggest the protagonist is being hounded by monstrous forces there is also a possibility that it is all delusion and the protagonist is suffering from extreme pyschosis (most likely paranoid schizophrenia).

History
the demons appear in the video frequently as the protagonist (via song) explains his inner fears of being watched / stalked, while taking a shower - although home alone the video shows a collection of monsters and mysterious figures constantly manifesting on and off in varied places, the protagonist grows more and more unstable as he proceeds to explore his home, convinced he is being pursued, all the while glimpses of the demons continue as do more disturbing phenomena.

Ultimately the haunting seems to end after the protagonist finds the mailman and calms himself, seeming to think the delusions are over and goes to reach for the mail - unaware that the mailman is hiding a rotting limb, grinning sinisterly..

Appearances
the demons appeared as many different creatures, most notable among them was a lean man dressed in nothing but a white towel, a phantom-like woman dressed in black, a zombie-like face in a mirror and a twisted mailman with rotting limbs : there are also glimpses of stranger entities lurking in the corners or through windows, some of which resemble strange child-like phantoms.

Abilities
by its very nature as a music video it is hard to determine what powers (if any) the demons possessed but they seemed to be vast and varied, with all the associated phenomena of an extreme haunting or demonic invasion - including the ability to manifest at will or disappear and cast frightening illusions; it is possible they may even be responsible for driving the protagonist insane (alternatively they are physical manifestations of the protagonist's already existing madness).