headrick

A big ugly birthmark that draws attention away from any positive aspect a person may have; a disturbing discoloration on the arm, face, etc. that grosses people out; anything to force the opposite sex away from a person who claims to look good

Dude why is that guy wearing a mask?
He's probably got a headrick he's trying to hide.
Oh, that's disgusting.

Aren't you going to talk to that girl?

Uh, no. Look at that headrick!
Ew.