Korg is part of the Kronan race . After his defeat at the hands of Thor when the Stone men tried to invade Earth, Korg became a prisoner of the Red King on the alien planet of Sakaar. He was forced into slavery by an obedience disk and made to fight for his life in the gladitorial arenas. Korg was made to kill his brother Margus against his will. This fact still haunts Korg to this day.
When the Hulk was exiled to the Red King's planet, Korg became the Hulk's ally after he and five others were victorious during one of the gladiator games that rule on the planet as a form of entertainment. Korg was the first to let the group talk to each other, and after more victories in the game, Korg became a gladiator. Still fighting alongside the Hulk, Korg was part of the group that rebelled against the Red King after the Silver Surfer used his Power Cosmic to destroy the disks that controlled the slaves. The Surfer had also been made a slave by such a disk, but it was destroyed by the Hulk when they were forced to battle. (In the DVD adaptation, it was Beta Ray Bill, not the Silver Surfer, using the lightning powers of his hammer, Stormbreaker, to perform this feat.)
After the detonation of Sakaar, Korg convinces Hiroim (who has lost his hope and wanted to stay to die) to come with him on the space ship. Korg was with the Hulk and the others and managed to knockout Wonder Man. However, after the discovery that Miek had triggered the destruction of Sakaar, Korg and the other surviving Warbound surrendered to S.H.I.E.L.D. custody, only to escape when earthquakes began to tear Manhattan Island apart due to the damage the Hulk had caused. Working with fellow Warbound member Hiroim and Earth hero Thing, Korg was able to heal the damage caused to the island, before he and his fellow Warbound retreated into the sewers.
Korg is also featured in World War Hulk: Frontline as a detective of sorts and is partnered up with a New York detective when investigating the death of Arch-E-5912. In the Avengers: The Initiative issue of World War Hulk, Korg is confronted by his fear when Trauma comes to rescue is fellow Cadets: Korg's worst fear is the Thunder god Thor.
In the miniseries Warbound, he helps in the defeat of the Leader who has turned a city in the middle of the desert into a new Gamma World but at the cost of Hiroim.
During the Chaos War storyline, Korg ends up helping the Hulks and A-Bomb fight a resurrected Abomination and the forces of Amatsu-Mikaboshi. When the Zom part of Doctor Strange is awakened by Amatsu-Mikaboshi, Marlo Chandler ends up using the death fragment to resurrect some of Hulk's allies.