George Maximilian was an up and coming athlete in Wrestling for his college university. He also had the rich backings of his father to allow him every opportunity to succeed and make it in the world. Unfortunately he decided that to win at all costs was better than honesty and began using strong steroid-like pills which not only enhanced his strength and speed, but amplified his aggression. Eventually he was kicked out of the university for accidentally killing a fellow wrestling competitor and kicked out of his home by his father who didn't want a junkie for a son.
Since that time George noticed the pills had a strange side effect. He developed strange mouth-like holes on his hands that, if he used them on people, would sap their strength and increase his own. Seeing this as a way to make him some money and to get his revenge, he donned a costume and named himself The Leech.
Leech like mouths on his palms allow him to suck the energy and strength of anyone he can get his hands on, allowing him to increase in strength and vitality.
He is easily provoked and when he is in a blind rage he can attack almost anything. Every time he gains strength, he becomes more like a mindless monster almost hulk-like.