Dr. Bruce Banner/The Hulk

The Hulk is a 9 foot tall creature that is the form of Bruce Banner when angered or stressed. This is due to exposure to gamma radiation during an experiment attempting to find a way of making humans immune to gamma radiation.

The Incredible Hulk
Bruce Banner was experimenting to make humans immune to gamma radiation, but when testing the experiment on himself, he transformed into the Hulk and hospitalized his lover, Betty Ross and injured her father, General Thaddeus Ross (who was hoping Banner would perfect his serum in order to re-create a super-soldier serum). Now a fugitive from the United States Army, Banner works in a soft drink bottling factory in Brazil while attempting to find a cure for his condition with the help of an Internet friend known to him as "Mr. Blue". To prevent another transformation, Banner undergoes rigorous meditation and keeps his pulse at a steady level.

After Banner suffers a cut, a drop of his blood lands into a bottle of soft drink eventually drank by an ill-fated consumer. Following the event, Banner is compromised and General Ross sends Emil Blonsky and a special forces team to apprehend him. While trying to evade the special forces, Banner is attacked by thugs and becomes the Hulk. The Hulk fights off the thugs and the special forces team and escapes leaving Blonsky unharmed. Banner wakes up in Guatemala, dazed by the experience and eventually makes his way to the United States, where he sees that a now-recovered Betty is working at Culver University and is dating psychologist Doctor Leonard Samson. He also sees his old friend Stanley, a pizzeria owner, who gives him a job as a delivery boy. Banner uses this job to sneak past a Culver University security guard to continue his research. One night Betty visits the pizzeria, and sees Bruce, later reuniting with him.

Blonsky reports to Ross that Bruce evaded them in Brazil because of the appearance of a large green monster. Ross explains that the monster is Banner, and that he was created accidentally during an experiment in radiation-resistance that, unbeknownst to Banner himself, was inspired by World War II (WWII)-era military bio-force enhancement research, or "Super-Soldiers", as Blonsky puts it. Blonsky, seeking both revenge and power, volunteers as a test subject in order to capture Banner, and receives a small dose of of the mothballed original super-soldier formula made in WWII by Dr. Reinstein. He leads an assault on Banner at Culver University, during which Betty is knocked unconscious. Despite Blonsky's increased strength, speed and agility, the Hulk crushes most of the bones in Blonsky's body before absconding with Betty to Smokey Mountain National Forrest. Banner and Betty then travel to Manhattan, where they meet Banner’s "Mr. Blue" Internet friend, Dr. Samuel Sterns. Accompanying Sterns to his lab, Banner and Betty learn that Sterns has developed a possible antidote that may reverse Banner's transformations after their occurrence but might not prevent future ones, while an overdose would possibly kill him. Despite the risks, Banner agrees to test Sterns' antidote and is restrained before being shocked into transforming with electricity and then reverted to normal with an injection of the serum and Betty's calming words. Exhilarated by the success of the antidote, Sterns reveals that he has synthesized Banner's blood sample into a large supply with the intention of using it to enhance the human condition to the next evolutionary level. Appalled by what his colleague had committed and fearful of the the Hulk's power falling into the wrong hands, Banner attempts to convince Sterns to destroy the blood supply when he is shot by a tranquilizer from one of General Ross' snipers.

As both Banner and Betty are taken into custody, Blonsky, whose super-soldier treatment has healed all his injuries but is desperate for more power, confronts Sterns and demands he subject him to a dose of the Banner's gamma radiation treatment. Sterns warns that the combination of the super-soldier serum and a gamma treatment would be an unpredictable combination and could turn him into an "abomination." Blonsky however is less than concerned about the possible consequences and Sterns promptly administers the gamma charge. As Blonsky mutates into a hideous titan, he knocks Sterns aside and an irradiated sample of Banner's blood-derivative drips into an open wound on Sterns temple, causing his cranium to mutate and expand as the Abomination goes on a rampage in the city, hoping to draw out Banner. Banner, realizing that he is the only one who can stop the Abomination, convinces General Ross to release him. He jumps out of Ross' helicopter as it hovers over the city, hoping the fall will stimulate his adrenal glands into triggering a transformation. Banner's plans succeeds and after a violent, pitched battle; the Abomination is defeated when the Hulk brutally strangles him with a huge chain but is stopped from killing him by Betty. After winning the battle, the Hulk flees the scene with the army in hot pursuit.

Thirty one days later, Banner is in Bella Coola, British Columbia. Instead of trying to suppress his transformations, he is attempting to initiate them in a controlled manner. As his eyes turn green, a grin appears on his face.

The Avengers
Once again on the run, Banner found a new direction for himself acting as an unregistered physician helping people in poverty-stricken slums. No longer obsessed with finding a cure for himself, he had gained peace of mind in helping others. One night while working, he found himself lured into a meeting with Natasha Romanoff, an agent of S.H.I.E.L.D., who proposed a job for him helping S.H.I.E.L.D. with a dire emergency. Initially dubious, and suspecting that S.H.I.E.L.D. was really after his green alter ego, Banner resisted, but eventually he relented and agreed to Romanoff's request.

His assignment on the S.H.I.E.L.D. Helicarrier was to track the location of the Tesseract, an object of limitless power that had fallen into the possession of Loki. He worked together on this project with Tony Stark, the industrialist also known as "Iron Man", and was introduced to others, who like himself, were also more than human. Almost immediately, the clash of personalities within this assembled group provided a constant source of tension for all and Banner was subjected to frequent reminders of his need to contain the beast within. When others of the group apprehended Loki, and the Asgardian was imprisoned on the carrier, the antagonism only got worse.

The Hulk finally boiled to the surface again when Clinton Barton, a S.H.I.E.L.D. agent under Loki's control, led an attack against the carrier. Explosions from the attack caused debris from the ceiling to rain down on Banner, injuring him and triggering the change. He first rampaged around the vessel hunting Agent Romanoff, before turning his attention on Thor on the hangar deck. Finally, a S.H.I.E.L.D. pilot in a fighter jet outside got his attention by shooting him through a window, causing the Hulk to leap out and fall.

Banner awoke in the blasted remnants of a warehouse and was immediately greeted by a lone security guard who offered him clothing. He was also relieved to learn that nobody else had been around when he crashed down.

Following disturbances into New York City, where Loki had opened a dimensional rift, Banner located his superhuman acquaintances assembling to counter the threat. Although they were wary of another transformation, they insisted that he would be a help. Banner obliged, triggering a controlled transformation, then together with the others, he turned his attention on the Chitauri invasion force pouring through the portal. The Hulk did indeed prove to be an asset to the group. Not only did he single-handedly kill the first of the Chitauri leviathans that came through the portal, he was an unstoppable force in dealing with individual alien warriors, and instrumental in capturing Loki.

Long after the battle was over, Banner, now back to normal again, gathered with the others to see off Thor and the captive Loki. The threat had been neutralised and for a time the world would have little need of its protectors. Banner and the remaining heroes said their goodbyes and parted company.