The Hulk is a fictional comic book superhero appearing in publications by the American publisher Marvel Comics. Created by writer Stan Lee and artist Jack Kirby, the character first appeared in the debut issue of The Incredible Hulk (May 1962). In his comic book appearances, the character is both the Hulk, a green-skinned, hulking and muscular humanoid possessing a vast degree of physical strength, and his alter ego Dr. Robert Bruce Banner, a physically weak, socially withdrawn, and emotionally reserved physicist, the two existing as independent personalities and resenting of the other. Following his accidental exposure to gamma rays during the detonation of an experimental bomb, Banner is physically transformed into the Hulk when subjected to emotional stress, at or against his will, often leading to destructive rampages and conflicts that complicate Banner's civilian life. The Hulk's level of strength is normally conveyed as proportionate to his level of anger. Commonly portrayed as a raging savage, the Hulk has been represented with other personalities based on Banner's fractured psyche, from a mindless, destructive force, to a brilliant warrior, or genius scientist in his own right. Despite both Hulk and Banner's desire for solitude, the character has a large supporting cast, including Banner's lover Betty Ross, his friend Rick Jones, his cousin She-Hulk, sons Hiro-Kala and Skaar, and his co-founders of the superhero team the Avengers. However, his uncontrollable power has brought him into conflict with his fellow heroes and others.