Subject: The Hulk (Bruce Banner)

Supervising the trial of an experimental gamma bomb for the U.S. Defense Department at a nuclear research facility in New Mexico, Dr. Robert Bruce Banner selflessly rushed to the rescue of an ignorant teenager who had wandered onto the testing field as the countdown ticked inexorably toward zero. After shoving young Rick Jones to safety in a nearby ditch, Banner was struck full-force by the bomb blast. He survived, but was irradiated by the deadly gamma energy.

At first, Banner would transform into the brutish gray Hulk only at sunset, and revert to human form at dawn. Eventually, his changes into the childlike green Hulk came to be triggered by the release of adrenaline when he was intensely excited, no matter what time of day. The green Hulk possesses little of Banner's memory and intelligence, and is easily enraged; making him a menace to society.

Powers:

The Hulk possesses an incredible level of superhuman physical ability. His capacity for physical strength is potentially limitless due to the fact that the Hulk's strength increases proportionally with his level of great emotional stress, anger in particular. The Hulk uses his super humanly strong leg muscles to leap great distances. The Hulk has been known to cover hundreds of miles in a single bound and once leaped almost into orbit around the Earth. The Hulk has shown a high resistance to physical damage nearly regardless of the cause, and has also shown resistance to extreme temperatures, poisons, and diseases in addition to regeneration of damaged or destroyed areas of tissue at an amazing rate.
The Hulk's body also has a gland that makes an "oxygenated per fluorocarbon emulsion", which creates pressure in the Hulk's lungs and effectively lets him breathe underwater and move quickly between varying depths without concerns about decompression or nitrogen narcosis.

Abilities
Dr. Bruce Banner is a genius in nuclear physics, possessing a mind so brilliant that it cannot be measured on any known intelligence test. When Banner is the Hulk, Banner's consciousness is buried within the Hulk's, and can influence the Hulk's behavior only to a very limited extent.