General Ross had always regarded the Hulk as something forbidden and precious. At first, Bruce Banner had been conducting an experiment with his daughter on using gamma rays to restore biological tissue. They used gamma rays on experimental frogs, but the process unexpectedly spiraled out of control. The gamma radiation suddenly intensified, and to save the other people in the lab, Bruce Banner used his own body to block the gamma-ray emitter. As a result, he mutated into the Hulk, gaining immense strength through anger.