Gonzo is a middle aged, half bald man. He has white colored hair and beard. He wears a standard black suit, with a white shirt. He also wears a pair of round shaped glasses.
Gonzo is extremely loyal to Roba, to the point of disobeying Ratchet if the two give different orders.
Gonzo worked for many years under Roba. In this period, he became very loyal to her.
The Giant Mechanical Soldier of Karakuri Castle
Gonzo appeared for the first time when the Straw Hats were invited to Ratchet's castle for a party. Chopper initially thought he was a robot, but Gonzo replied that he's a human while all maids are robots.
The next day, Ratchet awakened the giant tortoise and the Straw Hats started attacking the castle. The pirates fell into one of the traps, but Gonzo freed them under Roba's order. The woman tried to take the blame for her son's actions and Gonzo, fascinated, asked the pirates to be punished himself instead of the old woman.