An insufferable jerk you used to know - such as an arrogant jock in high school - who later is humiliated by baldness and must resort to a comb over or comb up, or alternatively just wears a hat all the time.
Friend: Did you see that dickhead Colt at the 10-year reunion?
Me: No, I heard he was too embarrassed to come because he's fat and bald now.
Friend: Wow, he really received his combuppance.
A "reward" i.e. well deserved and long awaited revenge for past misbehavior. The "reward" should be administered by those previously wronged and in a public or humiliating way.
That bitch will get her comeuppance in the form of a public birching at the next group pot luck. Everyone there will be quite pleased at the chance to participate. I don't think she will be able to sit down for several days.