Dr. Carl Maddicks was once the head geneticist working for the research firm known as the Brand Corporation, a subdivision of the Roxxon Oil Corporation. Maddicks was also secretly in the employ of the second incarnation of the subversive organization known as the Secret Empire.
Henry P. McCoy, a talented young biochemist who was secretly the mutant known as the Beast, took a position at Brand and, while there, concocted a chemical that could induce mutations. McCoy later ingested this chemical himself, causing him to mutate into his fur-covered, more animalistic form.
As punishment for the failure of his attempt to steal the formula for the mutagenic chemical, Secret Empire agents shot Maddicks and left him in a roadside ditch to die. But, unknown to them, Maddicks was found and taken to a hospital. During his recovery, the second Secret Empire was destroyed. Hence, Maddicks no longer needed to fear their retaliation.
Maddicks took a new job at Ryan Research, Inc. outside Atlanta, Georgia. His young son Arthur joined him in Georgia. His wife had died earlier. On his son's eleventh birthday, Artie's own latent mutations first manifested themselves, grotesquely altering his physical appearance and rendering him mute. Hiding Artie from public view, Carl Maddicks was determined to restore his son to normalcy.
Unable to make enough progress on his own, Dr. Maddicks, decided to force Henry McCoy, whose identity as the Beast was now publicly known, to help him. (Apparently Dr. Maddicks believed McCoy would never aid him voluntarily.) Dr. Maddicks hired Tower, a superhuman mutant being examined at Ryan Research, to abduct McCoy. Tower did so, and then Dr. Maddicks contacted the organization known as X-Factor to persuade them to capture Tower. At that time X-Factor was publicly believed to be an organization of mutant hunters; in fact, however, it was headed by the Beast's friends and partners, the original members of the X-Men.
Dr. Maddicks showed McCoy a copy of his work, trying to find a chemical formula to reverse the effects of mutation to the captive Beast. As Dr. Maddicks had predicted, the Beast began mentally solving the problems that had stymied Maddicks as an intellectual exercise. Dr. Maddicks had Artie use his new mutant powers to project upon a screen a vision of the forumlae that McCoy was working on. Dr. Maddicks was then able to concoct a chemical to reverse the effects of mutation. (The workings of this chemical remain unknown. Exactly how Dr. Maddicks can alter some of his subjects' genes but not others has not been disclosed.) Dr. Maddicks decided to use McCoy himself as a test subject, subjecting him both to the new chemical and radiation treatments.
Tower told X-Factor about Dr. Maddicks and X-Factor went to Ryan Research to rescue the Beast. McCoy was now comatose as a result of Dr. Maddicks' experiments. Distraught over McCoy's condition, Artie wanted no part of his father's experiments to cure him. X-Factor broke into Dr. Maddicks' laboratory at Ryan and confronted Dr. Maddicks, who then told them his story. Knowing that Ryan security forces were coming, and fearful that they would kill his freakish-looking son before he could stop them, Dr. Maddicks had X-Factor take Artie and McCoy to safety while he remained behind as a distraction. When the security forces arrived at his laboratory, Dr. Maddicks fired a gun at them, and they shot him. Dr. Maddicks is presumably now dead.
The Beast, as a result of Dr. Maddick's treatments, lost his furry form, reverting to his previous, more human one. Since then, however, the Beast has regained his fur-covered bestial appearance.
X-Factor took the orphaned Artie into their charge, hoping to train him in the use of his powers. Artie and other young X-Factor trainees became a team known as the X-Terminators, which was then incorporated into the team called the New Mutants.
Artie's main champion is a young mutant named Leech who was also a student of X-Factor. The two young mutants have been inseparable ever since.
source: http://www.angelfire.com/comics/benriely/