When Bruce was first exposed to radiation from the Gamma Reactor, Bruce became a large grey creature. However, this form quickly gave way to a more powerful green form that became known as the Hulk.
Bruce Banner's body was separated from Hulk after an experiment called the Nutrient Bath. But after the experiment Bruce's body suffered some trauma and that was because he couldn't live without the Hulk. There was an experiment where they reversed the effects of the nutrient bath, Thaddeus Ross wanted to stop the experiment but Rick Jones interfered trying to stop him. Rick was accidentally knocked into the nutrient bath and became a green combination of himself and Hulk. This stressed Banner that his friend had become a Hulk. He didn't want Rick to go through the same nightmare he had. He then transformed into the Grey Hulk. Grey Hulk fought the Rick-Hulk and defeated him. The Leader wanted Grey Hulk and Rick-Hulk's powers so he did an experiment where he would transfer their powers into his body. Rick-Hulk lost his powers and was cured. He became regular Rick Jones again but the Hulk escaped and stopped their plans. He then reverted into Green Hulk. Sometimes when Banner is angry he becomes Green Hulk but sometimes Grey Hulk. In Bruce's mind, the two wage a constant battle to see who emerges when Bruce becomes angry.
Bruce teamed up with his cousin She-Hulk. Once they encountered Miss Allure and Absorbing Man who were part of a crime syndicate and had influenced Bruce. She-Hulk and Grey Hulk teamed up become a rival gang, with Hulk taking the name Mr. Fixit.
When a Dark Entity possessed Bruce looking for a powerful body to inhabit, the mental images of the Grey and Green Hulks team up with Doctor Strange and She-Hulk to fight the creature while outside Bruce had becomeDark Hulk.
Unlike Green Hulk and Bruce, he does not seem to have much interest in Betty Ross.
- Robert Bruce Banner (Earth-400285) at Marvel Database
- Hulk (Robert Bruce Banner) (Earth-616) at Marvel Database