Grey Hulk

The original Hulk to appear when Banner first got hit by the Gamma Bomb. However, due to Banner's repeated use of gamma radiation projectors, the much better known/more common Hulk Green Hulk/Savage Hulk emerged. He also serves as the main protagonist in the second part of the Immortal Hulk comic book series. His rare appearances are also explained by saying that the Grey Hulk persona and the Green Hulk persona are battling in Bruce Banner's sub-conscious. Due to his superior strength, Green Hulk/Savage Hulk, won most of the time thus showing the Savage Hulk persona more often. but when the Green Hulk is separated from Bruce’s body in a nutrient bath, the Grey Hulk is the only one left.