Zombieman is the S-Class rank 8 hero in "One Punch Man" which is known as the man that even in death cannot die. He is a man with a scruffy black hair, red eyes and pale skin. He first appear in chapter 29 in the Manga and episode 10 in the Anime.
Zombieman is in S-Class, but in terms of destructive power he is considered as the weakest S-Class hero in "One Punch Man." Zombieman don't have any super strength or super speed but he battles enemies with the use of weapons like a Black Desert Eagle , a long bearded axe and a Katana and he is really proficient in using the said weapons.
Zombieman is really a normal person indeed, but his regeneration abilities is the best in "One Punch Man." He can regenerate any part's of his body and can keep moving even without head or innards. No matter how severe his injuries, he will just regenerate it.
Zombieman will just need to wait for a few minutes to regenerate any missing parts of his body or injuries. But even with this regeneration, he is still not immortal as he can die if he is reduced to mincemeat. With his regeneration ability, the name Zombie really fits his name in "One Punch Man."
Zombieman has a high endurance, it was first shown when he battle Pureblood, a Mysterious being during Monster association arc in "One Punch Man." Despite suffering 200 lethal would from Pureblood, Zombieman still manage to defeat this Mysterious Being. And because of his regeneration, He can battle Mysterious Beings for hours as he keep regenerating the damage that he receives.
One of Zombieman one on one fight with a Mysterious Being last 140 hours. This event made him somehow famous in the world of "One Punch Man." In the event of Monster association arc, He witness the power of Saitama thus believing that a human has a capability to remove his own limiter, a term in "One Punch Man" for someone to surpass owns strength, and he wishes to have his limiter remove to be equal with Saitama.
But Genos said that there are certain conditions to remove own limiter. Once "One Punch Man" Season 2 is aired, let's wait for Zombieman to have a blood splattering fights as all of his battles that happens in the Manga ends up Zombieman being injured gravely but easily regenerate it.