Created by the extraterrestrial Xemnu
, using Hulk (Bruce Banner)
's DNA, Kluh was designed to be the perfect opposition for Hulk, who Xemnu had an ongoing rivalry. When Xemnu returned to Earth, intending to kill Hulk before taking over the planet, he unleashed his creation. Kluh was initially stronger than Hulk, but a visiting Impossible Man
merged Banner's Hulk with the Red Hulk
, making them a composite Hulk and combining their strength. The amalgamation of both Hulks proved too great for Kluh to overcome, and he was defeated and thrown back through the portal he arrived from, presumably returning to his point of origin.