George Tarleton, also known as M.O.D.O.K. (Mental Organism Designed Only for Killing), formerly M.O.D.O.C. (Mental Organism Designed Only for Computing), was a lowly American technician working for A.I.M. (Advanced Idea Mechanics). He joined the team to help develop the Cosmic Cube, but was mutated into a human computer by the Scientist Supreme. They enlarged his brain to give him a superhuman intellect, but with the side effect of a massive cranium which was too much for his frail body, meaning that he needed to be placed inside a life support unit dubbed the "Doomsday Chair". The process also gave him a plethora of psychic powers along with an ego and ambition to match. He went on to use his newfound powers to take control of the organization that had experimented on him.