One Piece: The Strongest Merfolk

Key Takeaways

  • The Merfolk are genetic relatives of the Fish Man and have faced historical oppression and slavery.
  • Powerful mermaids like Hyouzou and Aladine can show off their powers in battle.
  • Shirahoshi is probably the most powerful mermaid because it is an ancient weapon.



mermaid Although somewhat niche, it is an active species. one piece. They are genetic relatives of the fish-man, the main difference being that the fish-man's fish-like characteristics are more prevalent above rather than below. Like fishmen, mermaids are also biologically compatible with humans, as the three races have a deeper ancestral relationship.

Nonetheless, due to historically oppressive attitudes and because mermaids were highly valued slaves, many of them were forced to remain underwater. Despite this, some mermaids have been shown to be perfectly capable of fighting for themselves. Some of these are: The strongest mermaid that appeared in one piece until now.


5 Hyojo

Officer/Dragon Sword of the New Fishman Pirates

Hyojo vs Zoro one piece


  • debut: Episode 607 (cartoon), Episode 527 (animation)
  • bell: Blue-ringed octopus mermaid

Hyojo A person who was once considered the strongest swordsman on Fishman Island. He was specifically scouted by Arlong, but their partnership never solidified as Arlong was unwilling to pay for his services. Hyouzou claims that Hatchan, an octopus fish skilled in swordsmanship, is instead part of the Arlong Pirates.

Hody Jones knew of Arlong's mistake and was willing to pay Hyouzou. The mermaid was ambivalent about Hody's ideals, but acted as an officer because she was paid. He is fast enough to stop Luffy in his Gear 2 form and has been shown to be able to eliminate many enemies. Similar to the blue-ringed octopus, it also has the ability to secrete toxins. Hyouzou was ultimately no match for Zoro, which was made worse after his excessive consumption of energy steroids rapidly aged him into a frail old mermaid.


4 Aladdin

First Mate/Doctor of the Sun Pirates

Aladdin surrounded by various fishmen and mermaid crew members, including Jimbei

  • debut: Episode 620 (cartoon), Episode 540 (animation)
  • bell: Goatbeard Brotula Merman

Aladdin He was once a slave along with his former captain, Fisher Tiger, and many of his crew. He is currently the only Sun Pirates member who was with the crew before Tiger's death and remains with them to this day. This is because most of his known crew members formed or joined other pirate crews after the fact. When Jimbei was captain, he became second-in-command, and due to Jimbei's own departure, it is likely that he is now captain.


In addition to her medical training, Aladine is also skilled in fishman karate, which allows her to clash with the likes of Charlotte Oven, the famous officer of the Big Mom Pirates. Like most mermaids, he is an adept swimmer, but unlike some, his body type allows him to stay on land without any additional assistance.

3 Neptune Brothers

Princes of the Ryugu Kingdom

From left to right: Ryuuboshi, Manboshi, Garp, Fukaboshi, and above, Shirahoshi, attending Levelly.

  • debut: Episode 609 (cartoon), Episode 528 (animation)
  • bell: Shark Merman (Fukaboshi), Oarfish Merman (Ryuboshi), Opah Merman (Ryuboshi)

Fukaboshi One of Neptune and Otohime's three sons and the next heir to the throne. Even in the midst of adversity between humans and fish, she is truly devoted to her mother's dream of a peaceful relationship with humans, just like her family. Compared to his younger brothers, he is overall more serious and loyal. Lyuboshi and 10,000 stepsThey are a more comical duo.


All three are very strong, and the New Fishman Pirates are forced to take energy steroids to replace their abilities. Unlike their fathers, all three are still in their relative primes, with Fukaboshi in particular showing the ability to recover from injuries fairly quickly. That said, once they consumed the steroids, they were no match for the pirates and had even more help from the Straw Hat Pirates and Jimbei.

2 neptune

Ruler of the Ryugu Kingdom

Neptune One Piece

  • debut: Episode 611 (cartoon), Episode 530 (animation)
  • bell: Coelacanth Merman


neptune The husband of the late Otohime, the beloved mermaid king who wishes for peace. Neptune worked tirelessly to keep his late wife's dreams alive and was generally well-liked by his subjects. He can also communicate with whales, a relatively rare skill for mermaids. He primarily uses it to communicate with his giant pet whale, Hoe, which also serves as a means of transportation.

Even in her 70s, Neptune is a powerful mermaid, able to withstand Hody's attacks even after the pirate's consumption of energy steroids. That said, his age has caught up with him, to the point where he can surpass even his physical endurance through excessive exertion in battle.

1 Shirahoshi

Princess of the Ryugu Kingdom

Shirahoshi in one piece standing in front of the blue sky

  • debut: Episode 612 (cartoon), Episode 531 (animation)
  • bell: Smelt Mermaid


Shirahoshi She is the only daughter of Neptune and Otohime. She is known for her enormous size, larger than her mother and older brother when she was less than a year old. She spends most of her life inside a locked tower, cared for by her family, and is quite fragile. Her vulnerability is such that Luffy called her a crybaby, especially when the two became close. She needed him to protect her as she left her quarters for the first time in years.

She tries to become braver to join her family for Revelry, but is quickly captured by Charlos, a world noble who wants to enslave her. Nonetheless, thanks to Leo's timely intervention between fellow world noble Don Quixote Mösgard and the Straw Hat Grand Fleet, the young mermaid was rescued.


Despite her current vulnerable state, Shirahoshi has the potential to be far more powerful than her relatives combined. This is because she is the ancient weapon of Poseidon, a trait she inherited from her distant ancestors. Poseidon's main asset is his ability to control and communicate with the Sea Kings, powerful beings who inhabit all known seas. They respond to Luffy's emotions and desires, such as her wish to receive help even if she did not directly ask for it. Aside from this fact, she can also increase her stamina if she wants, as her relatives are among the most powerful mermaids in existence.

Leave a Comment