Created during Sonic's journey in outer space, an event brought about by the battle between a massive force of Mobians and the alien Xorda, A.D.A.M. was the "brother" of Robotnik's feminine android Mecha, whose destruction he would later cause by framing her as an accomplice of an unknown enemy of their "father". He was the first villain to learn of Sonic's return, being in control of a SWATbot legion that was decimated by the prodigal hero shortly after his landing on Mobius. A.D.A.M. once engaged Miles "Tails" Prower in a battle of wits, but was defeated when Tails confused him by telling jokes. He also tried to take apart Bunnie Rabbot and integrating her into a small city composed entirely of nanites, but Sonic stopped him by convincing him that Bunnie's organic components would corrupt his software.
A.D.A.M was assigned to "determine the movements" of the mysterious being known as Anonymous, who had for several months been manipulating events involving the return of Mammoth Mogul and the villain's subsequent alliance with Ixis Naugus, putting two contenders out of his strategy and leaving only Sonic and Eggman for termination. Anonymous' actions also included creating robot duplicates of the Destructix, leading Robotnik to believe that someone had managed to subject them to re-Roboticization, something he had not accomplished since the mass de-Roboticization brought about by the Bem. It was eventually revealed that A.D.A.M. was, in fact, Anonymous, when Robotnik discovered his plans. The doctor had A.D.A.M.'s program destroyed, but ultimately, the program was one step ahead, and took Tommy Turtle's body as a host, an action made possible by nanites bonding to Tommy's shell through the Turtle's tears and an electric shock.
A.D.A.M. captured Tails and Shadow the Hedgehog, and he intended to use both to begin "the gathering", and assemble every Chaos Emerald in the universe within his headquarters, a city constructed by nanites. A.D.A.M. actually began this some time before he was exposed, releasing Mogul and Naugus from the Egg Grape Chambers in exchange for the former's Chaos Emerald. He was later destroyed along with Tommy Turtle, after Sonic transformed into Super Sonic, the other two teleported all the Chaos Emeralds into the Zone of Silence, and A.D.A.M. himself was vaporized by the Egg Fleet. Following the battle, Tommy's remains-and by association A.D.A.M.'s-were placed in the Knothole graveyard alongside those of Sir Connery. Ironically, Connery's self-sacrifice in destroying the Crown and Sword of Acorns and stopping Mammoth Mogul made him another of A.D.A.M.'s victims.
A.D.A.M.'s failed scheme provided Feist, the new ruler of the Special Zone, with near absolute power, as he fused all the gems into seven differently colored Emeralds. The only Chaos Emerald-like gem known to have escaped this was the Master Emerald, which was held back from A.D.A.M.'s summons by the combined efforts of Locke and Dr. Finitevus. Unwittingly, A.D.A.M. also left behind a gift for his enemies, as NICOLE later transformed his nanite city into New Mobotropolis.
Nanite-Possessed Tommy Turtle