The Incredible Hulk (a.k.a. Bruce Banner) is a fictional superhero that appears in comic books published by Marvel Comics. The character was created by Stan Lee and Jack Kirby, and first appeared in The Incredible Hulk #1 (May 1962).
Throughout his comic book appearances, the Hulk is portrayed as a large green humanoid that possesses near limitless superhuman strength and great invulnerability, attributes that grow more potent the angrier he becomes. Hulk is the alter ego of Bruce Banner, a socially withdrawn and emotionally reserved physicist who physically transforms into the Hulk under emotional stress and other specific circumstances at will or against it; these involuntary transformations lead to many complications in Banner's life.
Source: Wikipedia, "Hulk (comics)", available under the CC-BY-SA License.