Big Fat Bully
There was this dude in school who had a group of friends. The dude would sometimes get a little tipsy with the liquid courage and go off beating up some of the smaller dudes in school. All the dude's friends thought he was a jerk, but didn't really say much about it and definitely didn't do anything about it. They didn't like what they saw, but they appreciated the benefits the dude brought to the crew.Anytime someone else would pick on one of the school's underlings, the dude and his crew would chastise that other dude and threaten to throw down if things didn't change.
The more the dude drank, the weaker he became. All the while, the dude's friends, and even some of his "not-friends," sat back, watched, and waited until the dude became such a fat slob that anyone of them could step up and take his place as A-1-cool-kid in the school.