Kluh was a contestant in the Battle Nexus Tournament at the same time the Turtles first participated. He defeated a Fantasy Warrior in Tier 1, and Gorath in the second Tier. Between rounds, he met Michelangelo in the market area while in his small form. Michelangelo accidentally insulted him, and Kluh transformed into full size in order to pummel Mikey. Just before attacking Mikey, they were transported off for the next round of fights, where contestants paired up by picking colored darts. Initially Mikey was supposed to fight Kluh, but he tricked Zat into taking his place. Kluh defeated Zat and went on to defeat Gen in the semi finals, but was nearly drawn into oblivion only to be saved and defeated by Mikey (accidentally) in the final round of the battle. Following this, he was hired by Traximus to help overthrow the Prime Leader of Triceraton (albeit he still held grudge against Mikey).
Some time later, Kluh came to Earth to challenge Mikey for a rematch, ignoring that Mikey saved him from certain destruction. This time Kluh is with his father Ammag's assistance and with the goal of making Mikey pay for his defeat... in blood.
Despite gaining the upper hand in the battle, due to his sheer strength and various dirty methods employed by his father to offset the safety measures of the Battle Nexus, Kluh made a fatal mistake of insulting Mikey's family. These insults caused Mikey to get a second wind and Kluh realized he underestimated the turtle before he was overwhelmed and at his opponent's mercy. Kluh told Mikey to finish him but Mikey refused to stoop to his level and Kluh was again defeated by Mikey (honestly this time).
Kluh is very vengeful character and despises the rules of the Battle Nexus.
- Kluh and his ilk are not-so subtle references to Marvel Comics' The Incredible Hulk. Kluh himself not only transforms from a smaller, scrawnier, apparently more hapless version into a larger, more powerful form, but his name is also "Hulk" backwards. His father's name, Ammag, is "Gamma" reversed, and Gamma Rays are what first unleashed The Hulk from scientist Bruce Banner. Finally, their home dimension, Levram, is backwards for "Marvel".
- Before Grudge Match, Kluh was known as Arbir on 4Kids' character guides.