Dr. Bruce Banner was supervising the experimental trials of the gamma bomb for the U.S. military, when he halted the test to rescue Rick Jones, a reckless teenager who had driven onto the desert testing field on a dare.
A Soviet spy, Igor Drenkov, seeking to eliminate Dr. Banner and steal his gamma radiation secrets, detonated the bomb. Banner managed to save Jones by pushing him into a blast ditch, but he wasn't so lucky. Struck full-force by the gamma bomb, Banner survived but was irradiated by the otherwise deadly gamma energy, transforming him into the brutish Incredible Hulk!
Dr. Banner suffers from multiple personality disorder (MPD), due to a traumatic childhood. As a child Banner witnessed the death of his mother at the hands of his father. Each personality manifest as an individual creature, and the variety and number of personalities appear to be limitless.
The first of the three personalities that manifest was the Selfish or Grey Hulk, also known in later years as Mr. Joe Fix-It. The Hulk under the alias of Mr. Fix-It worked for the Las Vegas mob as an enforcer.
Current Form:
The Hulk
Other Forms:
The Hulk
Mr. Fix-It
The Professor
The Devil Hulk
War (Apocalypse's Horseman)
The Green Scar
The Hulk with the Uni-Power
Nul
The Hulk (Post-Phoenix War)
Doc Green