Koz was a human criminal who operated in the city of Canto Bight on the planet Cantonica. He owed a large amount of money to the Sixth Kin criminal organization, led by Wen Delphis; as a result, Delphis sent one of her lieutenants, Ariole Yu, and the sniper Just Lucky, to confront Koz. Yu and Lucky found Koz in Club Lazuli, where Yu fought off several of Koz's henchmen as Koz himself escaped through the back exit. Pursuing Koz, Lucky knocked him to the ground, and Yu threatened him. Koz was unfazed, however—a number of his associates surrounded Yu and Lucky, and Koz warned the two operatives that the Sixth Kin was doomed and that they were helpless to stop it.