Man who tires to put the moves on a girl while they are asleep by creeping up on them. This can also be someone who is relentless and does not stop at no the first time.
Both Chad and Eugene asked Suzy out on a date. Suzy is currently fucking Chad, while Eugene was called a creeper by Suzy. From this we can conclude that Chad is likely confident and handsome, while Eugene is probably a socially awkward ugly motherfucker.
One who is excessively creepy. They may stalk people (or "creep" on people). May lurk in corners, be socially awkward or odd, and in generalextremely creepy.