Guy Dax is a respected neurosurgeon. However, his gentle demeanor hides savage urges to kill and maim. Dax becomes a masked supercriminal to act out these urges, Le Bossu, or the Hunchback. He comes to Gotham as a special doctor visiting Arkham Asylum. Here, he contacts the Joker and enlists him to be in the Club of Villains. 
 
He employs masked henchmen dressed as Gargoyles. During a conflict with Batman in the sewers of Gotham, one of the Gargoyles are able to cut Batman with a knife coated in a chemical that allows easier brainwashing.
 
Dax is still visiting Arkham when Nightwing is brought in after his capture by  Pierrot Lunaire. He plans on lobotomizing Nightwing. When Jeremiah Arkham objects to the plan, he is beaten by the Gargoyles, and the Black Glove takes over Arkham.
 
Later, Dax makes the mistake of allowing the Joker view his "transformation" from Dax to Bossu. The Joker savagely cuts Dax's face with a straight razor, disfiguring his face in a manner simlar to his mask. While trying to lobotomize Nightwing whith a heavily wounded face, he is knocked out by Nightwing.
 
Six months later. Bossu has left behind his previous life to focus on his crimes. When torturing a man in Gotham, Bossu is apprehended by the new Batman and Robin.