Zombieman, a genetically engineered humanoid created by Dr. Genus as Subject No. 66 in the House of Evolution’s "immortal series," escaped the laboratory a decade before the main timeline, leaving the facility in ruins as the sole successful product of the project. Engineered with rapid cellular regeneration, he recovers from dismemberment, fatal wounds, and catastrophic injuries within approximately three minutes. Though lacking superhuman strength, his relentless endurance allows him to prevail through attrition, exemplified by a 140-hour battle against a Mysterious Being that solidified his reputation. As an S-Class hero (ranked 8, later 6), he combines tactical analysis with investigative precision. During the Monster Association Arc, he tracked Marshall Gorilla to the House of Evolution’s remnants, confronting Dr. Genus. The scientist revealed Saitama’s limiter-breaking feat, which Zombieman initially dismissed as implausible. However, during the Neo Heroes Saga, he sought Genus’s assistance to remove his own limiter, enduring brutal trials that inflicted torn limbs and internal trauma. In combat, he exploits regeneration to outlast foes. Against Pureblood, he sustained 200 lethal injuries before securing victory with improvised axes after exhausting ammunition. Facing Homeless Emperor’s energy assaults, he deduced the involvement of a cosmic entity called "God," which later revoked the villain’s powers, reducing him to ash. Within the webcomic continuity, Zombieman challenged Monster Garou despite foreseeing defeat, then pragmatically advocated for Garou’s execution before acknowledging the latter’s humanity and deferring to Saitama and Bang. Post-Monster Association, he collaborated with allies to counter emerging threats like the Neo Heroes, offering strategic guidance while declining direct leadership roles to mentor figures like Child Emperor. His pallid complexion, scruffy black hair, and crimson eyes contrast with a weathered coat draped over a black shirt. Reserved and methodical, he prioritizes mission efficiency over camaraderie, though flashes of dry wit surface—such as mocking Genus’s post-villain career as a takoyaki vendor.