Kozaky is the head researcher of the Supreme King's Army. His duty was to help oversee the creation of the ultimate Duel Monsters card, before he was challenged to a Duel by Jim Crocodile Cook, where he was soundly defeated. His demonic horns are preserved in the English dub, despite being removed in the international artwork of all the cards he appears in (minus "Dr. Frankenderp").

Non-canon appearances


Kozay in World Championship 2008.

In Yu-Gi-Oh! World Championship 2008, after the player defeats Blowback Dragon in a Duel, his lab will appear in World three Civilization. When the player goes to his research lab, he will ask the player if he/she is willing to be a part of his research Duel and the player will face the Inpachis in a Duel, except for "Charcoal Inpachi". After the player defeats the Inpachis, he will ask the player to get the volcano's secret treasure and give it to him. When the player finds the treasure and gives it to him. Kozaky will use the treasure on Gigobyte and Gigobyte will become Giga Gagagigo. Corrupted by power, he will ask the player for help. After the player defeats Giga Gagagigo, he will repay the player by showing him/her the gate to World four Darkness. By beating Giga Gagagigo, he will be unlocked as a single Duel opponent in Free Duel and by beating him ten times in Free Duel, he will be unlocked as a tag partner.



Kozaky plays a Rider Deck, featuring monsters that ride motorcycles. His main strategy appears to be swarming his monsters on to the field in an attempt to perform a One Turn Kill.

Anime Deck

World Championship 2008

Goodbye Kozaky


Opponent(s) Episode(s) Outcome
Jim Crocodile Cook 138 Lose
Community content is available under CC-BY-SA unless otherwise noted.