Zombieman, an S-Class Rank 8 hero, wields unparalleled regenerative abilities forged through his origins as Subject No. 66 in Dr. Genus’s clandestine "Immortal Series" at the House of Evolution. After escaping the lab’s destruction a decade before the main narrative, he joined the Hero Association, his grayish-pale skin, crimson eyes, and short black hair often framed by battle-torn attire—a black tank top and light coat frequently shredded mid-combat, left unrepaired by his regeneration. Functionally immortal, he rebounds from obliterated limbs or organs, though catastrophic damage can briefly incapacitate him. Wounds seal in minutes; limbs regrow within fifteen. Despite average physical strength among S-Class peers, he weaponizes endurance, ambushing foes with concealed axes, firearms, and blades. His infamous 140-hour duel against a Mysterious Being epitomizes his attrition-based warfare. Calculative and dryly humorous, Zombieman operates with icy pragmatism, masking a guarded loyalty to allies. He mentors younger heroes like Child Emperor yet grapples with nihilism, fearing bonds he’ll inevitably outlive. This contrasts his relentless pursuit of justice, driving him to dismantle threats like the Monster Association. His vendetta against the House of Evolution led him years later to Dr. Genus, only to discover Saitama and Genos had already neutralized the group. Learning of Saitama’s limiter-breaking power destabilized his understanding of strength. During the Monster Association conflict, he endured energy barrages from Pureblood and Homeless Emperor, exploiting his regeneration to gather intel on divine forces. In the Neo Heroes Saga, he reengages Dr. Genus, submitting to brutal trials to breach his own limiter. Concurrently, he unravels conspiracies as an investigator, balancing detached professionalism with covert protectiveness. A chain-smoker with a sweet-tooth, he cycles through outfits destroyed in combat. OVAs cast him in darkly comedic murder mysteries, where bystanders mistake his regenerating body for a corpse. Tensions with Sweet Mask underscore his struggle against being labeled a monster, even as he safeguards the humanity he inwardly doubts.