Generaly a person who dresses in all dark clothing and whines about everything.
These people whine how their parents hate them, and are just there to torment them, when their parents actually spoil them rotten.
Timmy: Oh look! It's Dave! But, why is he sitting in that corner in all black with a stupid hair cut whining about how his parents hate him?
Richard: Oh, it does seem he has gone emo for no reason. It seems we have lost another friend.