HISTORY: Henry McCoy was a brilliant intellect who rose to become one of Apocalypse’s foremost scientists. Under the tutelage of Nathan Essex, better known as Sinister, he devoted himself to advancing the science of genetic mutation. McCoy was instrumental in developing the processes used to create Apocalypse’s gene-spliced Infinite Army, a force that enabled the conquest of much of the world. Those mutants judged unfit for survival were routinely subjected to his brutal experimentation, as McCoy sought to engineer an unstoppable legion of enhanced mutants in service to his master.
McCoy also turned his experiments inward, attempting to transform himself into the perfect mutant. Instead, he became a creature of legend within the Breeding Pens: the Dark Beast. As Apocalypse’s reign neared its end, McCoy’s work grew even more extreme. He sacrificed thousands of mutants in pursuit of the ideal genetic synthesis. Jean Grey and Scott Summers ultimately liberated many of the captives held in the Breeding Pens. Recognizing that Apocalypse’s empire was collapsing, the McCoy fled by teleporting himself into the M’Kraan Crystal, gambling on the countless realities contained within.
McCoy found himself in Earth-616's reality some twenty years in the past and settled in New York to continue his experiments. He has given himself credit for creating the Morlocks, but whether he has been telling the truth remains to be seen. During this time, McCoy sent his agent Random to ally himself with the government mutant team X-Factor. Random ambushed X-Factor, captured the team's then-leader Havok, and brought him to McCoy for experimentation.
McCoy then sent his agent Fatale to seduce and capture the X-Man known as Bishop, the only denizen of "mainstream" reality who remembered the alternate timeline which McCoy hailed from. McCoy hoped to erase all memory of his original timeline by eliminating Bishop. Bishop escaped from Fatale with help from this timeline's version of Henry McCoy, the X-Man known as the Beast. During the fight, McCoy discovered that he had a counterpart in this timeline who was a member of the X-Men.
In order to infiltrate the X-Men and capture Bishop, McCoy kidnapped Beast and altered his own form to resemble Beast. McCoy was uncovered as an impostor by the entity known as Onslaught when the latter attacked the X-Men, and McCoy escaped. McCoy was eventually driven off by X-Factor, who had found and rescued the "real" Beast. McCoy was found and rescued by Havok, who had since escaped McCoy's control, and recruited McCoy into the reformed Brotherhood of Mutants.
