Green Hulk
Green Hulk Wolverine #144-145,148,176
Green Hulk has super human stregth, thick skin and a healing factor. Hulk can smash a tank with one punch. Green Hulk does lack intelligance
Grey Hulk
Grey Hulk Wolverine #7-8,
Grey Hulk has super human stregth, thick skin and a healing factor. Grey Hulk also has a mind of a genous. Grey Hulk turns back into Bruce Banner during the day. Grey Hulk went by the alias Mr. Fixit when he went to Madripoor to check on his boss's operation. Patch made Grey Hulk look like an idiot and made Grey Hulk destroy the operation Hulk was supposed to be checking on.
Dr. Robert Bruce Banner
Dr. Robert Bruce Banner Wolverine #7-8,
Robert Bruce Banner is the Human form of the Hulk. Robert Bruce Banner became the Hulk after a accident in an experiment exposed Dr. Banner to gamma rays. After that, everytime Dr. Banner got mad he would turn into the Hulk.