Harper is a professional thief with above average agility, stealthy and fighting skills. He has some skills with a handgun, though his favorite weapon are his own wits.
Harper was orphaned at an early age. He was taken in by a New York City street gang who became the only family he knew for several years. The name changed often, "Hell's Bloody Terrors", "Midtown Marauders" and "the Demons". Depending on who was leading at the time and what sounded more intimidating. Twelve-tear-old Harper was known as the Asp.
When 13-years-old, Asp and other seven members attempted their first real robbery. He was captured and took the rap for his family. He spend two years in a detention farm. He was 15 when released. At 19, Harper "graduated" to being a numbers runner for a larger gang. He was caught again and spend another two years in prison.
When 21-years-old, Asp decided to leave New York for good. He moved to Europe. He spend the next 13 years, active in Spain, Italy, France, etc. He reportedly spend years in prison. During a stay in a Paris prison cell, Asp met Miles Olddan. A life-long "gentleman thief", Arsène Lupin style. They became partners in escapades all around Europe and the Middle East.
In his mid-30s, Asp was looking for one last big score to allow himself and Miles to retire in comfort. He though he found it when learning of the existence of the Ruby Scarab. A mystical artifact, sought after by numerous archaeologists, sorcerers and adventurers. Harper concluded it would be easy to obtain the Scarab, sell it to one of its seekers, steal it and sell it again and again.
During a battle between the Living Mummy and the Living Pharaoh over possession of the Scarab, the Asp sneaked inside and easily stole the artifact. The Pharaoh attacked him with energy blasts, easily evaded by the agile thief. He was later confronted by N'Kantu but set the mummy on fire. He then sold the Scarab to Alexei Skarab, a distant descendant of the creators of the artifact.
Unfortunately for him, N'Kantu and Zephyr took Miles hostage. Forcing the Asp to steal back the Scarab on their behalf. With a Living Mummy as a partner-in-crime, Harper's stealth skills were negated. Skarab awoke and shot at Harper, wounding his arm. The trio soon understood they had common foes in the Elementals. They returned to recruit Zephyr and Miles. Only to find the Elementals had already captured their rogue member and the hostage had changed hands.
Harper surprised the elemental by physically attacking them. He knocked out Magnum and Hellfire, before being dehydrated by Hydron. Ron McAllister later managed to wound Hydron, allowing Zephyr to free herself and her fellow captives. The Asp was one of the participants in the final other-dimensional battle with the Elementals. Finding himself able to use the energies of the Scarab, he joined forces with his allies to banish the three male Elementals to a dimensional vortex.
Asp kept possession of the Scarab while vacationing on a Caribbean island with Miles and Zephyr. When Hecate and the other Elementals located them, Harper was forced to hand over the Scarab in exchange for Zephyr's life. He tried to warn Hecate that her "allies" were about to betray her, but Hellfire struck him down with an energy blast.
There is speculation that Asp and Miles were homosexual lovers, based on their interaction but to date this has not been confirmed on panel.