Banner is depicted as a genius physicist who, after a failed experiment to replicate a super soldier program using gamma radiation, transforms into a large, muscular creature with green skin whenever his heart rate goes above 200 beats per minute or when facing mortal danger.

In the years following the Blip, Banner learns to retain the Hulk form with his mind still intact, and he is instrumental in the Avengers' mission using time travel to obtain the Infinity Stones from the past to undo Thanos' actions.

After his cousin Jennifer Walters is accidentally imbued with his blood, Banner trains her to handle her newfound "She-Hulk" transformation before departing again to Sakaar.

The experiment — part of the World War II-era supersoldier program that Ross hopes to recreate — fails, and the exposure to the gamma radiation causes Banner to transform into the Hulk for the first time.

Five years later in 2010,[d] Banner works at a soda bottling factory in Rocinha, Rio de Janeiro while searching for a cure for his condition, collaborating on the internet with a colleague he knows only as "Mr. Blue", and to whom he is "Mr. Green".

After Banner cuts his finger, a drop of his blood falls into a bottle, and is eventually ingested by an elderly consumer in Milwaukee, Wisconsin, giving him gamma sickness.

Ross tracks down Banner, sending a special forces team led by Russian-born British Royal Marine Emil Blonsky to capture him.

Blonsky agrees to be injected with a similar serum, which gives him enhanced speed, strength, agility, and healing, but also begins to deform his skeleton and impair his judgment.

Still enslaved, Thor attempts to convince Hulk to help him save Asgard from Ragnarok, and then escapes the palace to find the crashed remains of the Quinjet.

He then accompanies the surviving Avengers, Danvers, Rocket, and Nebula back into space to the planet Titan II to confront Thanos only to find out he destroyed the Infinity Stones.

After doing so, an alternate version of Thanos emerges from the quantum realm and bombs the Compound, causing Banner, Rocket, and Rhodes to be trapped in rubble, until they are saved by Lang.

He then takes part in the final battle against alternate Thanos and his alien army, who are eventually defeated when Stark uses the Infinity Stones, at the cost of his own life.

Lee cited influence from Frankenstein[6] and Dr. Jekyll and Mr. Hyde in the Hulk's creation,[7] while Kirby recalled as inspiration the tale of a mother who rescues her child who is trapped beneath a car.

Feige, a self-professed "fanboy", envisioned creating a shared universe just as creators Stan Lee and Jack Kirby had done with their comic books in the early 1960s.

[16] In April 2007, Edward Norton was hired to portray Banner and to rewrite Penn's screenplay in order to distance itself from the 2003 film and establish its own identity as a reboot, although he would go uncredited for his writing.

The merged Banner/Hulk storyline depicted in Avengers: Endgame also differs from the comics, where a comparable merger was accomplished by hypnosis performed by superhero psychiatrist Doc Samson.

For The Incredible Hulk, Louis Leterrier stated that Edward Norton's rewrite of the script "has given Bruce's story real gravitas", explaining that "just because we're making a superhero movie it doesn't have to just appeal to 13-year-old boys.

[69] The Hulk only appears briefly at the beginning of Infinity War, with Bruce Banner spending the film trying to reintegrate with the Avengers, and to "impress upon everybody how dangerous Thanos is".

[81] Leterrier hired Rhythm and Hues to provide the CGI, rather than Industrial Light & Magic (ILM) who created the visual effects for Ang Lee's Hulk.

Visual effect company, Image Engine, spent over a year working on a shot where Banner's gamma-irradiated blood falls through three factory floors into a bottle.

Motion capture aided in placing and timing of movements, but overall key frame animation by Rhythm and Hues provided the necessary "finesse [and] superhero quality".

With 90 different expressions captured, ILM "built an entirely new library that would allow [Hulk] to cover a full range of normal human visual characteristics.

"[88] To help create the Hulk, a person on set was covered in green body paint, and would replicate the intended motions of the character to aid the visual effect artists.

Framestore completed nearly 460 shots, which featured digital doubles of Thor and Hela, Fenris, Korg, Miek, the giant Surtur at the end of the film, and over 9,000 buildings for Asgard, based on assets D Negative had from The Dark World, resulting in over 263 character, vehicle, prop, and crowd rigs.

[93] Conversely, Christy Lemire of the Associated Press found that "the inevitable comparisons to Iron Man, Marvel Studios' first blockbuster this summer, serve as a glaring reminder of what this Hulk lacks: wit and heart.

Despite the presence of Edward Norton, an actor capable of going just as deep as Robert Downey Jr., we don't feel a strong sense of Bruce Banner's inner conflict".

Joe Neumaier opined that his performance was superior to the rest of the cast; "Ruffalo is the revelation, turning Banner into a wry reservoir of calm ready to become a volcano.

[96] The Village Voice's Karina Longworth concluded: "Ruffalo successfully refreshes the Hulk myth, playing Banner as an adorably bashful nerd-genius who, in contrast to the preening hunks on the team, knows better than to draw attention to himself.

"[97] Travers asserted that the actor resonated a "scruffy warmth and humor" vibe,[98] while Turan felt that he surpassed predecessors Edward Norton and Eric Bana in playing the character.

[99] Owen Gleiberman of Entertainment Weekly wrote that "the smartest thing the filmmakers did was to get Mark Ruffalo to play Bruce Banner as a man so sensitive that he's at war, every moment, with himself.