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Sludge Jellyfish (ヘドロクラゲ, Hedoro Kurage; Viz: Hedro-Jellyfish) was a member of the Monster Association and an ally to Phoenix Man. It is one of the Mysterious Beings who assaulted S-City alongside Elder Centipede. He was killed by Child Emperor.[1]


One of its most notable features is that Sludge Jellyfish looks like a walking blob with two eyes. It has goop like skin and filaments. Because of its appearance, it leaves a trail like a snail.

After his first encounter with Garou, Sludge Jellyfish adopts a more humanoid appearance, and changes his form so that he now has two legs and several tentacles sticking out of him.


Sludge Jellyfish is one of the more friendly monsters to appear, alongside Phoenix Man. It even tried to invite Garou to join the Monster Association despite the latter attacking it. However, Sludge Jellyfish did not forget the incident and got revenge by holding Tareo as a hostage to mess with Garou. Like most monsters, he is rather fearful of powerful heroes such as King and Tatsumaki, and is scared at the mere mention of their name. However, he is rather impressed by the power of the Executive Members of the Monster Association, stating that it was as if they were created by "God" himself.

Like Phoenix Man, Sludge Jellyfish is one of the few rational monsters, who isn't prompt to kill humans or attack them on sight. He engages in a conversation with Tareo and Waganma.


Human Monster Saga

Monster Raid Arc

Sludge Jellyfish is first seen in S-City accompanied by Phoenix Man and Rhino Wrestler. The three monsters corner Mohican and Pineapple, who are carrying Narinki and his son Waganma.[2] Sludge Jellyfish is first seen watching the battle between Garou and Metal Bat alongside Phoenix Man.[3] After the fight was finished, it tried to kidnap Zenko, only to be intercepted by Garou and brutally smashed by him for watching over him.[4]
Sludge Capture

Sludge Jellyfish captures Tareo.

However, thanks to its regenerative abilities, Sludge Jellyfish survived Garou's attack. While angry, Sludge Jellyfish still tried to invite Garou to join the Monster Association. Unfortunately, the invitation was rudely turned down. Sludge Jellyfish then leaves alongside Phoenix Man.[5] He later surfaces again during Garou's fight with Bug God and Royal Ripper in which he captures Tareo to mess with Garou for attacking him earlier. His action causes Garou to be distracted long enough for Bug God and Royal Ripper to deal multiple fatal blows towards him, making Garou seemingly appear dead. Afterward, he, Royal Ripper and Bug God kidnap Tareo back as the Monster Association HQ as hostage.[6]

Sludge Jellyfish goes to the cell where Tareo and Waganma are being held, and tells them there is no hope for either of them to be saved. Waganma disagrees, and says the Hero Association has plenty of heroes, and goes off to list the names of several heroes, such as Metal Bat and King. At the mention of King's name, Sludge Jellyfish becomes frightened, but confidently states the whole purpose of the Monster Association is to eliminate such heroes, and goes on to mention the Executive Members of the Monster Association, speaking in awe of their strength and remarking they must have been created by God. He states that there is no way humanity can win, and even King will fall.

Sludge jellyfish death

Child Emperor burns Sludge Jellyfish into oblivion.

When Child Emperor breaks into Waganma's jail, Sludge Jellyfish attacks the hero. Filled with confidence in his liquid body, the monster arrogantly attacks the hero only to be blown apart by the oils Child Emperor injects into his body.[7]

Abilities and Powers

Not much is known about Sludge Jellyfish's strength, except that it's one of the few known monsters with regenerative abilities.

Physical Abilities

Homogenous Body: Sludge Jellyfish's body is made up of liquids and therefore has no discernible weak points. Physical attacks do not have much effect in damaging the monster. His body seems to naturally absorb all liquids including flammable liquids.

Regeneration: Sludge Jellyfish possesses great regeneration. It was able to regenerate back from a pile of goo after being smashed into the ground by Garou.

Poison Immunity: Sludge Jellyfish is immune to poison as shown when he was completely unaffected by Child Emperor's poisonous gas which killed several other monsters.[8]

Fighting Style

Hand-to-Hand Combatant

  • Sludge Press (ヘドロプレス, Hedoropuresu): Sludge Jellyfish attacks his opponent by launching his mass onto them.[9]


  1. One-Punch Man Manga; Chapter 97
  2. One-Punch Man Manga; Chapter 58, page 11-13
  3. One-Punch Man Manga; Chapter 58, page 48
  4. One-Punch Man Manga; Chapter 59, page 4-6
  5. One-Punch Man Manga; Chapter 59, page 7-9
  6. One-Punch Man Manga; Chapter 88
  7. One-Punch Man Manga; Chapter 97, page 22-25
  8. One-Punch Man Manga; Chapter 97, page 23
  9. One-Punch Man Manga; Chapter 97, page 22


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