Dr. Sugarman used to be a very prominent surgeon. Unfortunately he began to develop some emotional and psychological problems. He began to believe that the human body could be restructured so that it was perfect and immortal. He began some experiments on children, some of which left them in horrific unrecognizable forms, still alive for six days. After a while he decided that medical science wasn't enough and began to study the occult, making incredible progress, and becoming a formidable opponent. It is implied he has had conflicts with Julian Parker, Rabbi Sinnowitz, Nun Of the Above, and Catholic Girl (along with the organizations some of them represent) more than once prior to the series' beginning, and had been sealed away in the 'Wicker Castle' by All Hallow's Eve. He was apparently sprung by a group known as Trapeze 2 months prior to the start of Xombi via one of several methods of teleportation that leaves Nomatoads in its wake. He then began to turn back to science, taking an interest in the nanomachine research conducted by David Kim. He then created a small group of Rustling Husks and sent them to obtain the nanomachines for himself, while simultaneously setting up an apocalypse by setting Boraxis Megatheros, the Lord of Fumes, free from the Garden of Spires. He also sent Lesion Dogs, Butcher Babies, Sheer Shears, and Carnivore Clouds after those who sought to stop him, and at some point after his release gained several new abilities, including telepathy, creating a scorpion type beast from biting off someone's hand, and possibly more.
His efforts are all for naught, as the nanomachines he stole were programmed specifically for David, and therefore useless to him. However, he manages to escape and is presumed to still be at large.