Absolute Anime

Chumley is the third roommate of Syrus Truedale and Jaden Yuki. Despite the fact he's a third year student, Chumley is still is Slifer Red, due to a combination of exceptionally poor grades and dueling skills.

Chumley is at first, brash and prefers to sleep over dueling. His father comes to Duel Academy to take Chumley home, convinced Chumley is wasting his time there. With Jaden's coaching, Chumley duels his fahter for the right to stay. He loses, but his father overheard Jaden and Syrus helping Chumley's skills the night before, and lets his son stay with his friends.

Chumley wins a card design contest for Industrial Illusions, and Maximillion Pegasus offers him a job there: if his teachers agree. While Chancellor Sheppard eagerly agrees, Dr. Crowler is not so happy. Refusing to let Chumley take the job without graduating, Crowler duels Chumley: if Chumley loses, he gets the job. While Chumley pulls fof several powerful combos, Crowler still wins, but comforts Chumley: the duel wasn't to win, but to prove his skills. Crowler graduates Chumley and lets him leave to work for Pegasus.

Chumley and Pegasus reappear in season 2 when an Industrial Illusions employee steals a copy of the Winged Dragon of Ra. Using a Field spell of his own design, the employee is able to control Ra without envoking his wrath, but is defeated when his "Mounds of Binding God" is destroyed, and Ra rebells by reviving itself to Jaden's field and attacking the employee to win the duel for Jaden.

Chumley uses a Koala deck, and resembled a koala himself. Despite his poor skills, his best monster, "Master of Oz" has 4200 points, making it the 2nd strongest monster in either the anime or the real card game, second in power only to the Blue Eyes Ultimate Dragon... er... which is second in power to the Master of Dragon card... so I guess that'd made Master of Oz the third most powerful card.