There are many OCs that are terrible, the most common are the [Mary Sue], the Victim, the Not-OC and the Demon.
The Mary Sue is an absolutely perfect OC. They usually have bad pasts, never get angry, be skilled in every skill, have magical powers, be over powered, and never loses. They usually have the rarest abilities and are soooo unique. (Not at all).
The Victim is an attention whore OC. Someone with usually a cheesy cruel and sad back story. They probably had something awful happen to them, so bad it affected them forever.
The Not-OC is someone who completely clones either another OC or what the OC is parodying.
The Demon is one of the worst. Terrible past, ruler of other dimension or some crap, having powers that can destroy the whole world, being totally evil, having the colors black and red be everything about them. They never lose ever. Seems bad? They are!