One Punch Man's S-Class Rank 6 hero stands as a walking contradiction of death itself. Zombieman regenerates from wounds that would forever end any other hero's career. His ashen skin and crimson eyes reflect stories of endless deaths and revivals, making him perhaps the toughest warrior in the Hero Association.
The answer is both yes and no - Zombieman defies death through extraordinary regeneration but cannot claim true invincibility. His body rebuilds itself from fatal damage, including severed heads and destroyed organs, yet complete destruction would end his existence permanently.
Zombieman’s remarkable powers stem from his grim past as an experimental subject. Earlier known as Subject No. 66, he underwent vast experimentation that bestowed him his current regenerative capabilities. This background explains his nihilistic outlook and preference for working alone.

His regenerative powers are among the most impressive in the series. The hero can heal from wounds that would immediately kill ordinary humans, including massive head trauma and severed limbs. This ability has earned him a fearsome reputation, with stories claiming that "flowers of blood and slaughter blossom wherever he goes."
Zombieman's combat capabilities and limits of Regeneration in One Punch Man
Even with his healing abilities, Zombieman struggles significantly in direct hand-to-hand battles. He openly admits that fighting isn't his strongest suit, favoring stealth and investigation work instead. One Punch Man depicts how he repays for his relatively weaker physical strength via strategic thinking and specialized equipment.

His arsenal includes various firearms, machetes, and a distinctive long-bearded axe. The hero's trench coat features hidden enclosures and quick-draw systems that allow him to access weapons during battle. However, even with this equipment, he stumbles against opponents with overwhelming, lethal power.
Though Zombieman’s regeneration is remarkable, its limits prevent him from achieving absolute immortality. His regeneration needs time to work effectively, leaving him helpless during extended battles. More notably, there's a critical threshold beyond which even his powers cannot save him.
One Punch Man states that the complete destruction of his body would prove fatal. If shredded beyond recovery, Zombieman would meet a final end, showing that his so-called immortality carries absolute boundaries.
Contrasting Zombieman with Fellow S-Class Heroes in One Punch Man

Within the elite S-Class lineup, Zombieman occupies a truly unique place. One Punch Man proposes that he may be among the physically weakest members in terms of raw destructive power. However, his regenerative abilities and tactical intelligence compensate for these shortcomings in certain cases.
His thoughtful demeanor separates him from the more aggressive, combat-focused S-Class heroes. While many count on raw strength, Zombieman relies on resilience and perseverance to claim victory.
Recent plots in One Punch Man indicate Zombieman's growing displeasure with his current abilities. His urge to remove his limiter and achieve strength equivalent to Saitama implies he views his regenerative powers as lacking for true heroism.
As such, Zombieman exists in limbo between mortality and immortality within One Punch Man. Rather than indisputable power, his potency lies in psychological warfare against enemies who watch him rise repeatedly from obvious death. His regenerative abilities remake him into a ruthless force that refuses to stay down.