Erg was a member of the Morlocks who was able to absorb all forms of energy and project them in blasts from his left eye, which he called his "electric eye".
Erg was one of the few Morlocks to survive the Marauders' attack during the 'Mutant Massacre'. Shortly after the Mutant Massacre, Erg became the leader of the Morlocks.
Erg was one of the first mutants to seek a safe haven at the Xavier Institute following M-Day when most mutants lost their powers. Erg, Mammomax, and Peepers were running from members of the murderous Sapien League. They had the Institute in sight when they were taken down by a shock grenade and tasers. The Leper Queen ordered her men to kill them now. The League members set up three x-shaped St. Andrew's crosses with braces to keep the crosses upright. Erg was tied to one of the crosses, and gasoline was poured on and a lit match tossed. Erg regained consciousness when the lower legs of the cross were blazing. He would have died if he hadn't been yanked off by Wolverine, who had been sitting in the Xavier estate woods, letting Colossus sketch him.
It was Erg's idea to have a "198" flag on the grounds. He claimed he had an uncle, unnamed, who was a Hell's Angel and that the Hell's Angels wear a 1% badge because the media said it was just one percent of bikers who caused the trouble when a biker gang tore up a town called Hollister back in the 1940's. He was one of a few mutants who attacked Sentinel Squad O*N*E (Office of National Emergency) because they wanted to leave the Xavier estate. Mister M ended that fight.
Erg was also one of the unfortunate mutants who accepted having an electronic tag inserted in order to be allowed to go out on a supervised group trip to Salem Center. Dr. Valerie Cooper told the mutants that the tags were "...a harmless tracking device, inserted under the skin with a simple and painless surgical process." That wasn't true, as Erg figured out too late. Later on, Mister M took the liberty of freeing the chipped mutants of their devices. Erg later appeared under the leadership of Masque.
Erg was later seen on Utopia during the Second Coming of the Mutant Messiah, listening to X-Men leader Cyclops state to the non-X-Men Utopians that on that day, facing the Nimrods waves, they were all X-Men.
He then moved to Madripoor where a new mutant utopia was set up by Mystique's Brotherhood, leading a band of thugs and dealing Mutant Growth Hormone provided by the Brotherhood. After trying to beat up Magneto, he and his band were all taken down.