Hulk (also known as The Hulk) is a 2003 American superhero film based on the Marvel Comics character created by Stan Lee and Jack Kirby. The film was directed by Guillremo Del Toro and written by John Turman, James Schamus, and Michael France. Mark Ruffalo stars as Bruce Banner and Hulk, alongside Liv Tyler, William Hurt, Josh Lucas, and Ron Perlman. It is the second film in the Perfect Marvel Universe (PMCU). The film explores Bruce Banner's origins. After a lab accident involving gamma radiation, he transforms into a giant green-skinned humanoid with superhuman strength known as the Hulk whenever stressed or emotionally provoked. The United States military pursues him, and he clashes with his biological father.