They're the butt of almost any demeaning joke, they commonly have horrible luck, and a large amount of horrible things happen to them. Their existence is just to solely have horrible things happen to them. If anything positive happens to them, the person usually gets screwed over in the end.
Bill Dauterive from King Of The Hill.
2. A sycophant, or "brown-noser."
3. Someone who is extremely irritating or annoying, a "pain in the ass."
2. Jones is such a kiss-ass butt monkey.
3. Dammit! Would you stop being such a butt monkey and LEAVE ME ALONE?!