The Headsman is a criminal who first appeared to field test technology devised by Norman Osborn. He was sent to help the Enforcers escape from Spider-Man, which he accomplished by forcing Spider-Man to flee. Harry Osborn alerted Spider-Man to the criminals' meeting place, and the Headsman was forced to flee after the ensuing battle after Spider-Man damaged his power pack. After repairing his pack, Headsman teamed with Lucky Lobo to kill Spider-Man. Believing he had killed Spider-Man, he left the hero buried under a pile of rubble. Facing Spider-Man again, he was assaulted by the Green Goblin, who revealed himself to Headsman as his employer. The Green Goblin destroyed the Headsman's equipment and knocked him out, allowing Spider-Man to turn him over to the police.
Years later, the Headsman joined Osborn's Thunderbolts black ops team. He helped discredit Doc Samson by attacking Air Force One disguised as the Green Goblin. Osborn saved the President in a staged attack by tossing the faux "Green Goblin" from the plane. His teammate the Ghost revealed to him that the gravity-grip he used on his first mission was faulty and that he had fixed it, suggesting that Osborn had meant for him to die in his fall from the plane. The team's next objective was to kill Deadpool, at which they failed miserably. He battled new teammate Mister X, but was spared from death by the Black Widow.
The team battled Spider-Woman. During an operation that pitted the team against the Agents of Atlas, team leader Scourge was imbued with a post-hypnotic suggestion by the Uranian directing him to kill Osborn the next time he saw him. Following the operation, the team gathered around a holographic recorder featuring an image of Osborn. Scourge's post-hypnotic suggestion was triggered and he shot at Osborn, but the bullet instead passed through the hologram and struck Headsman, killing him.
After the fall of Norman Osborn's Dark Reign, Ant-Man paid a visit to Cleavon's brother, Cody, giving him the axe of Headsman and encouraging him to use it wisely by becoming a hero. 
Average: Cleavon Twain possesses the strength level of a man his age, size and weight who engages in moderate regular exercise.
The Headsman wears a power pack which enhances his strength.
Headsman Glider: Headsman rides a modified version of the "goblin glider", capable of great maneuverability and speeds of up to 90 miles per hour. It was capable of supporting about 400 lbs including Headsman's weight (and far more for very brief periods of time). Top speed and a full normal load would exhaust the fuel supply in about one hour. The main microprocessor assisted manual controls were behind the head of the glider, and later modifications added voice-activated radio-linked controls integrated into the Headsman's mask. The Headsman Glider was steered primarily, however, by the weight and attitude of its rider. The Headsman's boots are locked into the stirrups of the glider electromagnetically.
Headsman's Axe: Headsman uses an Axe developed from an unknown alloy. It is able to cut through various materials as strong as steel.
Headsman's name Cleavon Twain is derived from "cleave in twain," which means "cut in two," a reference to his use of his axe.