George Tarleton lived a relatively unassuming life before reaching adulthood. He was romantic with a woman named Linda Madigan while in college, but reportedly abandoned her when he learned she was pregnant. [Ms. Marvel (2nd series) #17] His father, Alvin Tarleton, was the founder of Advanced Idea Mechanics, a terrorist cell of brilliant scientists dedicated to shaping the world in their image. George was recruited into A.I.M. and seemed to be a capable mathematician, if unambitious. Perhaps this latter quality is why Alvin saw his son as a failure and made him serve janitorial shifts around A.I.M.’s headquarters. [M.O.D.O.K.: Head Games #4]
After the success of Project: Adaptoid, George had a one-night stand with another scientist, Monica Rappaccini. Monica was thoroughly unimpressed with George’s mind and quickly tired of him. Though Monica denied they had ever been dating, George saw their relationship as salvageable if only he could find a way to impress her. He stepped up and volunteered for Project: M.O.D.O.C. which, if successful, would dramatically increase the power of his mind. [Super-Villain Team-Up: M.O.D.O.K.’s 11 #1] When he saw the evolutionary accelerator chamber, George had his doubts and wanted to back out. Deemed one of the lesser and disposable intellects among A.I.M.’s ranks by his own father, George was forced to go through with the experiment. Tarleton was shoved into the alteration chamber and emerged as M.O.D.O.C., the Mental Organism Designed Only for Computation. His distorted, gargantuan head indeed contained a massively powerful brain which the Scientist Supreme put to work. [Captain America (1st series) #133]
Project: M.O.D.O.C. was designed to supplement other A.I.M. work into probing beyond the fabric of space-time itself. With M.O.D.O.C.’s computations and raw mental power, A.I.M. was successful in piercing the dimensional barriers using a meta-singularity, or grey hole. An X-Element unexpectedly emerged from the singularity, and A.I.M. captured this extra-dimensional force in a perfect cube, creating Earth’s first Cosmic Cube in the process. A.I.M. was studying its wish-fulfillment effect on reality when the Cube was appropriated by the Red Skull, then lost in battle with Captain America. In the meantime, M.O.D.O.C. had fumed under the inhumane treatment from his A.I.M. masters and dreamed of revenge. The strain of maintaining the singularity only deranged M.O.D.O.C.’s mind further. Eventually, M.O.D.O.C. became powerful enough to strike back, killing the Scientist Supreme and many of the ruling committee responsible for his transformation. [Captain America Annual #7]
M.O.D.O.C. became M.O.D.O.K., reprogramming himself to be Designed Only for Killing. A.I.M. fractured into many sub-factions with the death of the Scientist Supreme, but M.O.D.O.K. seized power over a substantial force of A.I.M. scientists and equipment. Many of his men feared him more than respected him, but their service was all M.O.D.O.K. required. He appropriated a massive A.I.M. submarine as his mobile base and began making moves to consolidate power.
This got the attention of S.H.I.E.L.D., and they dispatched Agent 13 Sharon Carter to infiltrate A.I.M. and learn more about the mysterious M.O.D.O.K. To prove herself, Sharon pretended to turn traitor and sell Nick Fury’s location to A.I.M.’s assassins. S.H.I.E.L.D. intended to sacrifice a Fury Life Model Decoy to sell her cover story, but Captain America visited S.H.I.E.L.D.’s secret base that day and interrupted the assassination.
The real Nick Fury filled Cap in on the situation and he hunted down A.I.M.’s submarine to rescue Agent 13. Captain America was captured and brought aboard the submarine where he was reunited with Sharon Carter. M.O.D.O.K. was self-conscious about his altered appearance at this point, and typically communicated with his underlings only through an obscuring screen. He ordered Carter to his private chambers to be interrogated, but his disgusted henchmen wanted to be free from M.O.D.O.K.’s control, so they sent Captain America through to M.O.D.O.K.’s chambers too. Captain America and Agent 13 started a fight with M.O.D.O.K., allowing the
rebellious A.I.M. agents to strike, destroying M.O.D.O.K.’s support chair. Hesitating between firing on M.O.D.O.K. again or Captain America, the A.I.M. agents were overcome by the Star-Spangled Avenger, who escaped with Agent 13. The vindictive M.O.D.O.K. triggered the submarine’s detonation sequence, seemingly killing himself and the other A.I.M. agents as Cap and Sharon sped to safety. [Tales of Suspense (1st series) #93-94]
M.O.D.O.K. survived, however, using an aura of mental force to shield himself from the submarine’s destruction before contacting agents still loyal to him for recovery. M.O.D.O.K. reclaimed control over his faction of A.I.M. and learned that the missing Cosmic Cube had once again been claimed by the Red Skull. M.O.D.O.K. declared that none but A.I.M. would profit from the Cube’s power. Under his direction, A.I.M. constructed a catholite block and re-forged it into a perfect sphere. Through unknown science, the catholite resonated remotely with the Cosmic Cube and caused the Cube to melt away as Captain America and the Red Skull fought over possession of it. [Captain America (1st series) #117-119]
M.O.D.O.K.’s transformation was not inherently healthy for the human body, and over time he began to suffer side effects. Disease and organ failure were common in his distorted frame, and so M.O.D.O.K. developed a “body farm” of sorts when he regularly grew clones of himself. Higher brain functions were disabled so the clones weren’t sentient, but instead served as organ donors to surgically replace elements of his body when they failed. M.O.D.O.K. also preserved the brains of his clones as organic computers and hard drives for A.I.M. installations around the world. Paranoid and legitimately hated by many of his subordinates, M.O.D.O.K. kept these facilities isolated and fully automated, with his surgeries performed by machines he personally programmed for the job. [Fall of the Hulks: Red Hulk #1]
M.O.D.O.K.’s next scheme for A.I.M. involved Paul Fosgrave, a mathematics professor at Manning University and top government consultant on atomic equations. M.O.D.O.K. wanted to steal Fosgrave’s work without implicating A.I.M. He planted two agents among the Manning students who used a hypno-beam to turn student leader Mart Baker into a rabble-rousing troublemaker. Under the cover of a student riot, M.O.D.O.K.’s agents were to kidnap Fosgrave and steal his work. Unfortunately for him, Nick Fury put Captain America on the case, posing as an athletics instructor at the college and he foiled M.O.D.O.K.’s plot. [Captain America (1st series) #120] After a failed assassination attempt on Cap, M.O.D.O.K. re-engineered one of the assassins as his new powered agent, the Cyborg. M.O.D.O.K. controlled the Cyborg thanks to a micro-wave energizer powering his body which only M.O.D.O.K. could recharge. Unfortunately, even the power of the Cyborg could not beat Captain America, and Nick Fury and S.H.I.E.L.D. tracked down M.O.D.O.K.’s base of operations, forcing him to flee. [Captain America (1st series) #124]
Captain America soon disrupted another attempt by A.I.M. to undermine America’s institutions for higher education. M.O.D.O.K. watched on as Cap foiled the schemes of Baron Strucker as well and became intent on crafting his revenge. M.O.D.O.K. made contact with Doctor Doom and requested a perfect robot duplicate of Bucky Barnes for his plot, appealing to Doom’s ego that he could not make a robot which could fool even Bucky’s old partner. Next, M.O.D.O.K. planted the “Bucky” robot out in the world while telepathically inspiring Strucker to seek revenge on Captain America by finding a Bucky look-alike. In this manner, M.O.D.O.K. hid his own involvement in what was to come. Captain America defeated Strucker as M.O.D.O.K. predicted and was emotionally reunited with the amnesiac “Bucky.”
When the moment came to strike, M.O.D.O.K. triggered the robot’s secondary programming, directing it to murder Captain America for “leaving him to die” aboard the rocket. M.O.D.O.K. hoped that Cap would be hesitant to defend himself against his partner if his survivor’s guilt was properly manipulated. In the end, however, Doom did his work too well, and the simulacrum of Bucky Barnes’ personality refused to harm Captain America any more than the real Bucky would have. The robot short-circuited and died rather than deliver the killing blow. [Captain America (1st series) #130-132]
M.O.D.O.K.’s next attempt on Captain America’s life came from an android called the Bulldozer. Sent to a disenfranchised section of New York City where Cap and the Falcon were meeting, the Bulldozer was programmed to shout modern protest phrases as it destroyed the local slums, making the locals believe A.I.M. was on their side against the establishment. Captain America and the Falcon were hard-pressed to convince the civilians that Bulldozer and A.I.M. were dangerous. Cap contacted Tony Stark, who quickly designed a portable energy detector to locate the abandoned church from where M.O.D.O.K. was controlling the Bulldozer Man. M.O.D.O.K.’s mistake was trusting no one but himself to direct the android, and so the Bulldozer was actively controlled by M.O.D.O.K.’s mental energy. With M.O.D.O.K. distracted fighting Captain America and the Falcon, the Bulldozer Man became confused and went wild without direct commands. Its rampage toppled the church, causing the building to collapse on top of M.O.D.O.K., seemingly killing him. [Captain America (1st series) #133]
M.O.D.O.K. survived the collapsing building by using a force field to shield himself against debris and then tunneling down to a waiting escape transit. He fled to a submerged A.I.M. base and swore off the fallibility of human agents, preferring to employ only androids in his endeavors. M.O.D.O.K. was in the process of re-harnessing the Cosmic Cube’s power when Doctor Doom and Sub-Mariner attempted to steal it. M.O.D.O.K. considered using the Cube to transfer his mind into Namor’s body and escape his current grotesque shape, but the plan failed. The Sub-Mariner overpowered him and the Cube’s radiation broke down the A.I.M. base, causing vast devastation which M.O.D.O.K. barely escaped. [Sub-Mariner (1st series) #47-49]
Perhaps reluctantly, M.O.D.O.K. returned to working with human agents in A.I.M. He established a vast network of informants to collect data and feed him intelligence reports, keeping his computer-like mind engaged and searching for useful connections from disparate information. After his encounter with Namor, M.O.D.O.K. recognized that his great mind could still be overcome by great strength. He resolved to build a massive robot body to have access to physical power when he needed it, and A.I.M. scientists succeeded in building this body to his specifications. M.O.D.O.K. also identified the incredible Hulk as the greatest source of physical power which could potentially be turned against him and plotted to remove that threat.
Perhaps through this network of agents, M.O.D.O.K. learned of psychiatrist Leonard Samson. Doctor Samson had studied Banner’s case and theorized a means of transference to move gamma radiation from one host to another. M.O.D.O.K. saw the potential of Samson’s ideas and devoted A.I.M. resources to bringing this “Cathexis-Ray” into existence. Although he failed to cure the Hulk entirely, Samson did drain off enough of Banner’s gamma rays to deliberately transform himself into the gamma-powered Doc Samson. M.O.D.O.K. approved of Samson’s success and left him alone for the time being, taking Samson’s data to continue his own experiments. [Hulk (2nd series) #18 / Incredible Hulk (2nd series) #141]
M.O.D.O.K. theorized that he could create his own gamma mutate to eliminate the Hulk for him. The ideal subject would be someone easy to control and already conditioned by previous exposure to gamma rays. An opportunity presented itself when M.O.D.O.K.’s informants told him of Betty Ross-Talbot. Major Glenn Talbot had seemingly died rescuing General “Thunderbolt” Ross from Russia, leaving his wife and Ross’ daughter Betty a widow. M.O.D.O.K.’s informant witnessed Betty having a mental breakdown at the airport when her father told her the news, hysterically screaming how she hated her father and all that he stood for before passing out. Betty’s history of exposure to the Hulk and her current mental state made her ideal for M.O.D.O.K.’s plans.
M.O.D.O.K. visited the sanitarium where Betty was recovering, covertly using his mental powers to bend her hatred towards the Hulk and plant hypnotic programming in her subconscious. Bruce Banner had heard about Betty’s condition, however, and his alter ego the Hulk fixated on visiting Betty to make her feel better. The Hulk found M.O.D.O.K.’s robot body outside Betty’s window and attacked. M.O.D.O.K. soon realized he was correct to fear the Hulk, for even his steel-and-adamantium frame and vast power could not defeat the creature. The Hulk ripped M.O.D.O.K.’s battle body apart until the leader of A.I.M. jettisoned from the stripped robot frame and made his retreat. M.O.D.O.K.’s work with Betty was successful, though, and she soon left the sanitarium on her own in a trance and delivered herself to M.O.D.O.K.
M.O.D.O.K. used a gamma ray transformer on Betty Ross, triggering a change into a winged creature he named the Harpy. M.O.D.O.K easily directed the hate-filled Harpy towards the Hulk, hoping a gamma-charged Betty Ross could succeed where he failed. The Harpy did knock the Hulk unconscious in the streets, but “Thunderbolt” Ross soon arrived on the scene after recognizing Betty in news footage. Ross’s presence was uncomfortable enough for the Harpy to grab the Hulk and fly away rather than finish him there. Surprisingly, the Harpy and the Hulk were captured by the Bi-Beast, last creation of the Bird People of Sky Island. M.O.D.O.K. followed the gamma trails of his creation to Sky Island and confronted the Bi-Beast, while Bruce Banner tried to cure Betty and escape with her. A.I.M. attacked the Bi-Beast, so it triggered Sky Island’s self-destruct, forcing M.O.D.O.K. to flee empty-handed of any success at all. [Incredible Hulk (2nd series) #167-169]