One Piece: 8 Strongest Filler Characters, Ranked

The One Piece universe is full of incredibly powerful characters. Over the manga’s twenty-eight years, creator Eiichiro Oda has introduced a huge cast, including famous heroes like Monkey D. Luffy and Shanks, fearsome villains like Kaido and Big Mom, and even strong, but corrupt, officials from the Marines, such as the Admirals.

Interestingly, some of the most powerful fighters in *One Piece* actually originated in the anime, not the original manga. Toei Animation created several characters specifically for the anime series, and many of them turned out to be incredibly strong. With over fifteen filler story arcs, there are plenty of anime-exclusive characters, but here are eight of the most impressive examples.

Caroline

The Substitute Queen Of Kamabakka Kingdom

Debut: Episode 454
Arc: Straw Hat’s Separation Serial Arc

Some *One Piece* fans might think Caroline, who temporarily rules Kamabakka Kingdom when Emporio Ivankov is away, is a character from the original manga. However, Caroline was actually created for the anime series. They didn’t appear in the manga’s side story that showed what Sanji was doing during the time skip with the Okamas.

I’m seriously impressed by Caroline – she’s an incredibly skilled fighter! She’s a master of Newkama Kenpo, which is this really unique and effective fighting style. Actually, she’s quite famous in the fighting world because she was the very first of the ninety-nine Newkama Kenpo masters Sanji had to overcome to learn all ninety-nine of his amazing Attack Cuisine recipes during his training. It’s a testament to her skill that she was the first one he faced!

Largo

Wields The Powers Of A Surprisingly Versatile Devil Fruit

Debut: Episode 426
Arc: Little East Blue Arc

Largo might not appear very strong at first. He leads a small pirate crew, the Amigo Pirates, and is the villain in a fairly standard story arc called the Little East Blue Arc. However, his true power comes from his Devil Fruit ability.

Largo has a unique ability gained from the Ami Ami no Mi: he can transform anything he eats into nets – even things like hot water, fire, or barbed wire. This surprisingly useful power allowed him to defeat and capture Luffy, Zoro, and Sanji when they first met. He can also turn parts of his own body into nets and use them to absorb powerful attacks.

Breed

This Cruel Beast Tamer Hides A Secret Power-Up

Debut: Episode 625
Arc: Caesar Retrieval Arc

Breed is the primary villain in the Caesar Retrieval Arc. He’s a brutal pirate who captures and controls creatures, and he uses the Peto Peto no Mi—a unique Devil Fruit—to create special collars. These collars force anyone who wears them to obey his every command, effectively turning them into his enslaved “pets.”

Watching Breed operate is pretty intimidating. He commands a huge force of powerful sea creatures – everything from Kung-Fu Dugongs to a giant Kraken! But what’s really dangerous is his Devil Fruit ability. Apparently, if he puts on one of his own special collars, it unlocks his full power, transforming him into this massive, incredibly strong beast. I saw him go toe-to-toe with both Luffy and Law all by himself – it was a serious fight.

Don Accino

The Patriarch Of The Accino Family Ate A Powerful Devil Fruit

Debut: Episode 326
Arc: Ice Hunter Arc

The Ice Hunter Arc is a particularly unique and engaging filler storyline in the *One Piece* anime. What sets it apart is that the main villains, the Accino Family, are bounty hunters – a change from the usual pirates or marines. Leading the family is the powerful Don Accino.

Don Accino is a powerfully built, talented, but easily angered man who possesses a remarkably strong Devil Fruit—the Atsu Atsu no Mi. This fruit grants him abilities similar to another Devil Fruit, allowing him to drastically raise his body temperature, especially when he’s furious. He can also generate and launch scorching heat balls as projectiles. Though incredibly powerful, Luffy ultimately triumphed over Don Accino in a difficult fight, reclaiming his crew’s stolen flag.

Bill

The Leader Of The Silver Pirate Alliance Is A True Force To Be Reckoned With

Debut: Episode 746
Arc: Silver Mine Arc

Even though Bill looks ordinary and his name doesn’t sound intimidating, he’s surprisingly powerful within the world of *One Piece*. He leads a huge group of pirates known as the Silver Pirate Alliance and serves as the primary villain in the Silver Mine Arc.

Bill is a popular and self-assured pirate captain, and he has a unique ability thanks to the Gutsu Gutsu no Mi, a Devil Fruit. This fruit transformed him into a human furnace, allowing him to eat and melt metal to forge weapons, fire hot metal fragments, and even cover himself in a metallic shell. Without Bartolomeo’s strong defenses from his Bari Bari no Mi, Luffy wouldn’t have been able to win against Bill.

Mad Treasure

He’s Strong, Unpredictable, And Ate A Powerful Devil Fruit

Debut: Heart of Gold (TV Special)
Arc: Heart of Gold Arc

Similar to many villains in the arcs that happen after the time skip, Mad Treasure is remarkably strong – comparable to some of the most powerful characters in the main story. He’s a notorious treasure hunter and leads the Treasure Pirates, a crew that works for Gild Tesoro, a powerful villain who first appeared in a *One Piece* movie.

I’ve heard a lot about Mad Treasure – he’s known for being completely unpredictable and a seriously skilled fighter. His Devil Fruit, the Jara Jara no Mi, fits him perfectly. It lets him create what seems like an endless supply of chains, which he uses in combat both to attack, like with whips, and to protect himself by covering his body with them. He was a really tough opponent; I witnessed him going head-to-head with agents from CP0 and even managing to capture most of the Straw Hat Pirates using his chains. Eventually, Luffy found a way to overcome his defenses and knock him out, but it wasn’t easy!

All-Hunt Grount

A Heroic Marine Captain Who Ate A Mysterious Zoan Devil Fruit

Debut: Episode 780
Arc: Marine Rookie Arc

All-Hunt Grount is a compelling character created specifically for the *One Piece* anime. He’s designed as a playful take on typical shōnen anime heroes, which is clearly shown in his intense rivalry with Monkey D. Luffy. As a Marine Captain trained by Kuzan, Grount is a skilled and clever fighter, but he’s best known for the powerful, unnamed Zoan-type Devil Fruit ability he possesses.

Grount can turn his left arm into a massive, powerful limb resembling a beast’s – covered in red fur and equipped with sharp claws. However, he struggles to control this transformation, often losing himself to its power. This enhanced arm gave him incredible strength, allowing him to battle Luffy directly, and while he ultimately lost, he began to gain control of his abilities towards the end of the fight. If Grount fully masters his Zoan transformation, he has the potential to become one of the most powerful Marine Captains in the world of *One Piece*.

Byrnndi World

A Terrifying Pirate Captain With A Practical Devil Fruit And Mastery Of Armament Haki

Debut: 3D2Y: Overcome Ace’s Death! Luffy’s Vow to his Friends (TV Special)
Arc: 3D2Y Arc

When it comes to powerful pirate adversaries Luffy has faced outside the main story, Byrnndi World from the *3D2Y* special is arguably the strongest. He’s a seasoned pirate who’s been sailing for over thirty years, leads a skilled crew including Gairam and Sebastian, and was once held in Impel Down’s notoriously secure Level 6 – until Luffy’s escape attempt freed him.

World’s incredible strength and diverse abilities are what allowed him to become such a formidable opponent. He possesses the Moa Moa no Mi, a Devil Fruit that lets him grow the size of anything he touches, and he’s a master of Armament Haki, able to coat his body for extra defense. He also knows several Rokushiki techniques, including Soru and Geppo. Most minor villains in the series aren’t much of a challenge for Luffy, but Byrnndi World was different. It took a significant effort for Luffy to defeat him, especially considering the fight happened during his difficult two-year training period.

2025-10-14 16:38