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You're looking down on me... aren't you?
~ Black Sperm to Atomic Samurai

Black Sperm (黒い精子, Kuroi Sēshi) is a major antagonist in the anime/manga One Punch Man. He is a mysterious being and one of the few Dragon Monsters in the Monster Association. Black Sperm makes his first appearance known during the S-Class heroes' raid on the Monster Association. 


Black Sperm has a humanoid appearance where his body is completely black. His face is the only thing that stands out as it is white. He also has an antenna on his head, in the shape of a sperm cell.


Hey, you brat! Wait up! I'm not gonna do anything much to you, I'm just going to kill you, that's it! Boom, you're dead, it will be over in an instant!
~ Black Sperm to Tareo

Black Sperm is very boastful about his abilities but is easily quick to temper whenever looked down upon. He seems to care little for humanity, as he was prepared to kill a child without hesitation. Every time his cells fuse together, he is shown to be more arrogant about his power. In addition to this, he cares very little for his other copies, as he wants them to simply merge with him.


Monster Association Arc

Black Sperm was present during the Monster Association meeting, where Gyoro Gyoro gave out a speech. Black Sperm claims that no one is here to serve Orochi and that they're simply here for their own motives. Gyoro Gyoro then states that if anyone believes Orochi is an unfit leader, they can take on leadership themselves by challenging him, in which Black Sperm notes.

Black Sperm chases Busaiku.

Black Sperm later attempts to kill Busaiku, who was trying to escape from the Monster Association's hideout. He was confronted by Atomic Samurai, who he eventually defeated with relative ease. Black Sperm later battled Tatsumaki, who was greatly weakened by Psykos, giving him the advantage. Together, he and Gums proceeded to reduce Genos is a heavily damaged state. Once Bang was knocked out by the Homeless Emperor, Black Sperm proceeded to take out Bomb.

Black Sperm continued to beat Genos, until King decided to confront him on his own. The monsters simply observe King and plan on their next move, which gives Tatsumaki enough time to recover. Gaining back her footing, Black Sperm uses his cells to form his Multi-Cell form, only for it to be destroyed effortlessly by Tatsumaki.

Golden Sperm beats Tatsumaki.

Black Sperm then proceeds to take Busaiku hostage and forms his cells once more into Golden Sperm, which later takes out Tatsumaki in less than a second.

All heroes except Tornado, please form a line and wait for your turn to be killed.
~ Golden Sperm

Golden Sperm has the heroes down to their feet, until Garou arrives to the scene, who has mutated into a powerful monster. Golden Sperm attempts to kill him, but he is overwhelmed and easily finished off by Garou. With one cell remaining, Black Sperm decided to take flee.

Psychic Sisters Arc

After the defeat of the Monster Association, Black Sperm soon met up with Overgrown Rover, who was weakened as well, due to its size being drastically reduced. The two meet Saitama and act as his followers, until they are later taken by the Hero Association, where they are being held in care.

Powers and Abilities

Do you still think you can win? I am a countless number of 'me' merged into one entity. No matter how you cut or tear, how you strike, crush, twist, I'll keep multiplying.
~ Black Sperm to Atomic Samurai

Black Sperm's shapeshifting abilities.

Despite his silly appearance, Black Sperm is one of the most powerful members in the Monster Association. Being a Dragon leveled threat, he is a true force to be reckoned with, as he has an arsenal of powers and abilities. These include:

  • Immense Speed and Reflexes: Black Sperm is surprisingly a fast being. His regular form was able to evade Atomic Samurai's attacks and keep up with Genos' speed, while his Golden form was able to blitz Tatsumaki without any effort.
  • Immense Strength: Black Sperm displays a great amount of superhuman strength. He was able to injure Atomic Samurai greatly in one hit and was capable of lifting up a huge boulder with ease.
  • Immense Durability: Black Sperm is a very durable being. In his regular form, he was able to tank all of Genos and Atomic Samurai's attacks, while his Golden form could not even be scratched by Tatsumaki's attacks.
  • Shapeshifting: Black Sperm is able to increase in size and manipulate his body shape in any kind of form.
  • Regeneration/Replication: Black Sperm is capable of regenerating himself by fusing with miniature cells of himself. These cells can also form separately to create a replica of Black Sperm. It should be noted that if the cells merge into one being, they will not regenerate once Black Sperm's been killed. Black Sperm can also increase his sperm stock by eating protein.

Multi-Cell Form: Multi-Cell is the form that Black Sperm that takes when less than 10 trillion cells combine together. The true strength of this form is unknown, but it can be assumed that his powers and abilities were augmented to a large degree, though less than his Golden form.

11 trillion, 449 billion, 1 million, 712 thousand, 554. That is the current number of "me" inside of me.
~ Black Sperm revealing his cell stocking ability.

Golden Form: Golden Sperm is the form that Black Sperm takes when 10 trillion cells have been fused together. In this form, his strength, speed, and skill increase to an insane degree to the point where a weakened Tatsumaki could not even react to his movements, though according to the author, ONE himself, if Tatsumaki was at full power, she could have actually beaten Golden Sperm, since she was only defeated in a weakened state.



           One Punch Man Logo.png Villains

Monster Association
Orochi | Psykos
Black Sperm | Elder Centipede | Evil Natural Water | Fuhrer Ugly | Homeless Emperor | Gouketsu | Gums | Nyan | Overgrown Rover
Notable Members
Gale Wind | Hellfire Flame | Phoenix Man
Bakuzan | Choze | Volten | Hamikichi | Benpatsu |

Dark Matter Thieves
Notable Members
Geryuganshoop | Groribas | Melzargard

House of Evolution
Dr. Genus | Genus' Clones
Notable Members
Armored Gorilla | Beast King | Carnage Kabuto | Ground Dragon | Mosquito Girl | Praying Mantis

Ninja Village
Ninja Village Leader
Notable Members
Gale Wind | Hellfire Flame | Speed-o'-Sound Sonic

Notable Members
Deep Sea King | Lord Great White

Paradise Group
Notable Members

Ancient King | Crablante | Garou | Kombu Infinity | Pluton | Sky King | Vaccine Man | God | Marugori

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