Stan Lee has repeatedly cited classic monster duality as core inspiration—especially Frankenstein and Dr. Jekyll and Mr. Hyde—for the concept of a man wrestling with an uncontrollable other self. Jack Kirby also leaned into the “Frankenstein in all of us” idea when describing why the Hulk worked as a character people could relate to. That’s the genius of the Hulk: He’s not just a superhero. He’s a myth. A warning. A mirror.