MODOK has a new large warm gold head mould depicting his dark brown hair, a purple headband with a red jewel in front, the front also has a large screen featuring a light nougat face with white eyes, wrinkles and a mouth all bent into an angry expression. He has a plain gold torso and purple limbs.
George Tarleton is a scientist working for Advanced Idea Mechanics (A.I.M.). He had experiments done on him that turned him into a giant floating head (combined with a supercomputer) known as the Mental Organism Designed Only for Computing. But Tarleton became corrupted and became the evil villain, the Mental Organism Designed Only for Killing (or MODOK for short).
He teamed up with Red Skull to swap the bodies of Red Skull and Captain America as Red bodies. However, MODOK used his powers to strip Iron Man of his armour (including the arc reactor keeping him alive) and put it on Red Skull to keep him alive. Later, MODOK unleashed swarms of mind-controlling robots upon the Avenger's mansion that infected all but Iron Man and was defeated by Iron Man, who cured his teammates. MODOK then helped Red Skull (who had placed a bomb in the mansion's reactor core) and himself get away and formed the Cabal with him which also included Dracula and Attuma.
At the beginning of the duel M.O.D.O.K. is invincible - so fight with his minions for some time and wait for the malfunction of the enemy's shield. When it occurs, switch into Thor and throw your hammer at the villain, so you can hit him during conventional melee fight. After first hit, the criminal will jump to the water - so you must spend some time struggling with his troops.
Notice that the whole sequence described above must be repeated for three times - only then the talking head will be finally vanquished.