Pierre the Gambler, known in Japan as Mitsuo (ミツオ, Mitsuo) is Alexis Rhodes' childhood classmate and a world famous gambler, having mastered games from blackjack to poker. In primary school, Pierre would play games of chance with other students, always having them bet their prized possessions. After losing a game of Duel Monsters to Alexis, he steals her red hankerchief, which had been bet on the Duel. Years later, he duels Alexis at Duel Academy but loses. In the end, it is revealed he actually has a crush on Alexis and returns the handkerchief to her. However, Alexis does not return these feelings and Pierre then leaves with Jaden Yuki trying to bid him farewell in the right way.
In Yu-Gi-Oh! GX Tag Force, Pierre appears as an opponent during the Tag Force tournament, teaming with Blair Flannigan. After completing the game, he appears during part one at the pier, and can be selected as a partner, though the player must call his coin toss correctly. He is referred to simply as "The Gambler", with his in-game profile being the only place where his real name, Pierre, appears.
Pierre speaks with a French accent in the English version. In the Japanese version, his nickname is "Boy", and he seems to intensely dislike being called "Mitsuo". In the Spanish version, he has the nickname "El Tahúr" (which means professional of gambling or person whose job is a gambler).