Marvel’s jacket copy of The Immortal Hulk goes like this: “Horror has a name. You’d never notice the man. He doesn’t like to be noticed. He’s quiet. Calm. Never complains. If someone were to walk up and shoot him in the head… all he’d do is die. Until night falls. And someone else gets up again. The man’s name is Banner. The horror is The Immortal Hulk.”
Marvel’s The Incredible Hulk has had a lot of incarnations. His original incarnation by Lee and Kirby was a Jekyll and Hyde story with a scientist turning into a gray-skinned monster each night. They found that gray-skinned monster blended into the gray night-time scenes so the Hulk soon became green and more of a science fictional anti-superhero who fought high-science communist threats and briefly joined the Avengers.