Monkey D. Luffy has encountered dozens of villains during his adventures, including a few who should have joined the Straw Hat Pirates.

Since its debut in 1997, One Piece has earned a spot as one of the most popular media franchises in the entire world. Its manga has sold more volumes than any other franchise in history, and if the recent success of its anime and live-action adaptations are any indication, the series is showing no signs of slowing down.

By the conclusion of the Wano Country Arc, Monkey D. Luffy has traveled across the majority of the Grand Line and met hundreds of different characters. This includes dozens of villains, some of whom share plenty in common with the Straw Hat Pirates despite their antagonistic relationships. Given One Piece‘s history of redeeming its antagonists, these characters could have joined Luffy’s crew, even if their introductions suggested otherwise.

10. Buggy Is The Only Emperor Of The Sea Who Could Have Joined The Straw Hat Pirates

Debut: Chapter 9 / Episode 4

Age: 39

Voice Actor: Shigeru Chiba (JAP) / Mike McFarland (ENG)

Devil Fruit: Chop-Chop Fruit

As far as One Piece villains go, none have been part of the series longer than the primary antagonist of the Orange Town Arc, Buggy the Clown. The red-nosed pirate is one of the first villains that Monkey D. Luffy encounters, and throughout the Straw Hat Pirates’ journey, he demonstrates himself to be among the most charismatic — and inept — pirates in the Grand Line.

Compared to the other primary antagonists who appear in the East Blue, none have more chemistry with the Straw Hat Pirates than Buggy the Clown. A true anti-hero has yet to join Luffy’s crew, and even though Buggy doesn’t perfectly fall into this category, he would add some significant nuance to the Straw Hat Pirates’ ranks. However, his recent coronation as an Emperor of the Sea makes it highly unlikely that he ever tags along with One Piece‘s protagonists for any significant amount of time.

9. Hatchan Becomes One Of The Straw Hat Pirates’ Staunchest Allies

Debut: Chapter 69 / Episode 31

Age: 38

Voice Actor: Toshiyuki Morikawa (JAP) / George Manley (ENG)

Excluding the legendary swordsman Dracule Mihawk, the Arlong Pirates are the most significant villains that the Straw Hat Pirates encounter in the East Blue. Along with being capable fighters, these fish-men are deeply connected to One Piece‘s lore, as several members of the crew previously served under the deceased leader of the Sun Pirates, Fisher Tiger. Tiger is arguably the most influential fish-man in One Piece, and as a result, characters like the Arlong Pirates’ resident swordsman, Hatchan, continue to appear throughout the series after being defeated by the Straw Hat Pirates.

Hatchan makes his debut as one of the Arlong Pirates’ strongest officers, but in both the Sabaody Archipelago and Fish-man Island Arcs, he shows a kinder side by assisting various characters, including the Straw Hat Pirates. Were Hatchan stronger in combat, he would have made an excellent addition to Luffy’s crew.

8. Bon Clay Sacrifices Himself For Luffy On Two Separate Occasions

Debut: Chapter 129 / Episode 78

Age: 32

Voice Actor: Kazuki Yao (JAP) / Barry Yandell (ENG)

Devil Fruit: Clone-Clone Fruit

The Alabasta Saga is where the Straw Hat Pirates truly announce their presence to the rest of the Grand Line, so it’s fitting that the sequence includes some of the best antagonists in all of One Piece. The criminal organization known as Baroque Works is full of memorable villains, one of whom — Nico Robin — even joins the Straw Hat Pirates after the conclusion of the saga. However, she’s not the only member of the organization who had a legitimate reason to join the crew.

Bon Clay, referred to as Mr. 2 within Baroque Works, develops a unique bond with the Straw Hat Pirates after running into them several times in the Alabasta Saga. In fact, the eccentric antagonist even distracts the Marines as Monkey D. Luffy and his crew escape Alabasta Kingdom — a noble act that parallels his sacrifice in Impel Down several arcs later. While adding both Robin and Bon Clay to the Straw Hat Pirates during the Alabasta Arc may have felt like a lot of change in a short amount of time, it’s clear that the latter would be more than welcome aboard the Thousand Sunny.

7. Bellamy Comes To Appreciate Luffy And The Straw Hat Pirates

Debut: Chapter 222 / Episode 146

Age: 27

Voice Actor: Wataru Takagi (JAP) / Justin Cook (ENG)

Devil Fruit: Spring-Spring Fruit

Although the Jaya Arc is one of the shortest in One Piece, it explores several of the series’ most important themes. In this arc, the Straw Hat Pirates are mocked for their aspirations, and no character is more critical of them than the user of the Spring-Spring Fruit, Bellamy.

When Bellamy the Hyena first appears, he ridicules Monkey D. Luffy for his lofty dreams, but after being defeated by the Straw Hat Pirate, he starts to rethink his perspective on life. By the time the pair reunite in the Dressrosa Arc, Bellamy has a begrudging respect for Luffy, making him one of the roundest villains in the series. Seeing him join the Straw Hat Pirates would have been a great way to wrap up his character arc, but thankfully, his retirement from piracy was an equally fitting end to his story.

6. Bartholomew Kuma Cares About The Straw Hat Pirates’ Well-Being

Debut: Chapter 233 / Episode 151

Age: 47

Voice Actor: Hideyuki Hori (JAP) / Joel McDonald (ENG)

Devil Fruit: Paw-Paw Fruit

The Seven Warlords of the Sea are an influential group of pirates who are sponsored by the World Government, allowing them to legally conduct operations that would normally result in their imprisonment. This makes them natural enemies to the Straw Hat Pirates, who declare open rebellion against the World Government as early as the Enies Lobby Arc. As a result, One Piece‘s protagonists attract the ire of several different Warlords, none of whom are more intimidating and mysterious than Bartholomew Kuma.

Bartholomew Kuma is immensely powerful, and in both the Thriller Bark and Sabaody Archipelago Arcs, he effortlessly dispatches the Straw Hat Pirates. However, it quickly becomes clear that Kuma is more than a villainous extension of the World Government — he’s a sympathetic figure navigating life to the best of his abilities. He separates the Straw Hat Pirates to save them from Admiral Kizaru and the other Marines, and he guards the Thousand Sunny throughout the entirety of One Piece‘s two-year timeskip. Although Kuma’s path seems destined for tragedy, he more than deserves a spot among the Straw Hat Pirates, who seem to be his only hope at achieving a happy ending.

5. Aokiji Grows To Appreciate Monkey D. Luffy’s Perspective

Debut: Chapter 303 / Episode 225

Age: 49

Voice Actor: Shigeru Chiba (JAP) / Mike McFarland (ENG)

Devil Fruit: Ice-Ice Fruit

One Piece spends most of its narrative following the Grand Line’s pirates, but in reality, most of the world is governed by a different group: the Marines. The military branch of the World Government is home to many of the series’ strongest fighters, but none are mightier than their highest-ranking officers, the Admirals. Aokiji, Akainu, and Kizaru are the Admirals when One Piece‘s narrative begins, and of the three, Aokiji easily has the deepest connection to the Straw Hat Pirates.

Even before Monkey D. Luffy’s journey as a pirate begins, Aokiji is forging relationships with some of Luffy’s closest allies. As a student of Luffy’s grandfather, Monkey D. Garp, Aokiji views the world much more similarly to the Straw Hat Pirate than the other Admirals, and as evidenced by his decision to save Nico Robin, he has no problem disobeying the World Government to do what’s right. The Straw Hat Pirates consist of characters from a variety of backgrounds, yet none of them are former Marines. This, as well as Aokiji’s recent departure from the World Government, make him one of the most intriguing potential Straw Hat Pirates in One Piece.

4. Kaku Is More Similar To The Straw Hat Pirates Than The Members Of Cipher Pol

Debut: Chapter 323 / Episode 230

Age: 25

Voice Actor: Ryotaro Okiayu (JAP) / Alex Organ (ENG)

Devil Fruit: Ox-Ox Fruit, Model: Giraffe

Of the World Government’s various branches, none are more mysterious than Cipher Pol. The organization answers directly to the Celestial Dragons, and as a result, they conduct highly secretive missions throughout the Grand Line. Rob Lucci, the villainous assassin who serves as the primary antagonist of the Enies Lobby Arc, personifies what Cipher Pol is looking for in an agent. That said, the organization also employs figures like Kaku, who forges an unexpectedly friendly rivalry with Roronoa Zoro and the Straw Hat Pirates during their time together.

Unlike Rob Lucci, who is a ruthless killer to his very core, Kaku possesses an undeniable affability and sense of empathy. It clearly pains him to turn his back on Paulie and the people of Water 7, and after being defeated by Roronoa Zoro shortly after, he even gives the Straw Hat Pirates the key to Nico Robin’s handcuffs in a legitimate display of honor. Although Kaku continues to rise up the ranks of Cipher Pol following the Enies Lobby Arc, his personal motivations are much more closely aligned with One Piece‘s heroes, potentially hinting at a change of heart in the series’ final saga.

3. Perona’s Bond With Zoro And Hatred Of Blackbeard Makes Her A Natural Ally

Debut: Chapter 443 / Episode 338

Age: 25

Voice Actor: Kumiko Nishihara (JAP) / Felicia Angelle (ENG)

Devil Fruit: Hollow-Hollow Fruit

The Thriller Bark Arc stands out from other One Piece arcs for several reasons, the most obvious of which are its spooky theme and unorthodox power-scaling. However, the most noteworthy part of the sequence is the colorful personalities of Gecko Moria and his crew, who serve as the primary antagonists of the arc. Their ranks consist of eccentric figures like Absalom, Hogback, and Perona, the latter of whom goes on to forge a unique bond with Roronoa Zoro during the series’ two-year timeskip.

Perona is far from the most evil character in One Piece, but at the same time, she is initially presented as an enemy of the crew. This makes her bond with Roronoa Zoro all the more surprising, as she nurses the swordsman back to health after he arrives on Kuraigana Island following the Sabaody Archipelago Arc. While this doesn’t inherently suggest that Perona would make a good Straw Hat Pirate, her willingness to help Luffy’s crew escape their reunion at Sabaody Archipelago and shared disdain for the Blackbeard Pirates are more than enough to assert her as a potential addition.

2. Señor Pink And Franky Are Birds Of A Feather

Debut: Chapter 702 / Episode 632

Age: 46

Voice Actor: Kazuhiro Yamaji (JAP) / Ethan Gallardo (ENG)

Devil Fruit: Swim-Swim Fruit

Although the Straw Hat Pirates have faced off against several notable groups since the conclusion of One Piece‘s timeskip, they are far more evenly matched against the Donquixote Family than any other faction in the New World. Almost every single member of the Straw Hat Pirates enjoys a solid one-on-one during the Dressrosa Arc, including Franky, who squares off with the most complex follower of Donquixote Doflamingo, Señor Pink. Señor Pink works as an officer of the Donquixote Family, and although there’s no question that he is a villain, he is a much more sympathetic figure than most of his peers.

Señor Pink has been part of the Donquixote Family for at least 16 years, during which he has assassinated an untold number of individuals. However, a decade before the events of One Piece, Pink fell in love with an innocent woman named Russian, who eventually learned of his true profession and promptly left him in disgust. Since then, Pink has dedicated himself to honoring their bond — a dedication that clearly impresses Franky during the duo’s battle. In fact, Señor Pink and Franky forge such a strong bond that the latter expresses his desire to reunite in the future, perhaps foreshadowing Pink’s appearance in the series’ final saga.

1. Kaido’s Obsession With Joy Boy May Lead Him To Follow Luffy

Debut: Chapter 795 / Episode 736

Age: 59

Voice Actor: Tessho Genda (JAP) / David Sobolov (ENG)

Devil Fruit: Fish-Fish Fruit, Model: Azure Dragon

The Emperors of the Sea are the most fearsome pirates in the Grand Line, but even among their ranks, none are more intimidating than the World’s Strongest Creature, Kaido. The captain of the Beast Pirates represents the pinnacle of raw strength in One Piece, and as evidenced throughout the Raid on Onigashima, he is more than capable of fighting multiple of the series’ strongest characters at the same time.

While it’s hard to imagine Kaido serving under any other pirate, he holds a notable amount of reverence for the legendary figure known as Joy Boy. At one point, Kaido even states that Joy Boy is the only individual who can defeat him — a prediction that comes true when Monkey D. Luffy awakens his Devil Fruit and reaches Gear 5. Assuming that Kaido survives this conflict, it’s legitimately possible that he acknowledges One Piece‘s protagonist as the heir to Joy Boy and takes up arms under the Straw Hat Pirates’ (or the Straw Hat Grand Fleet’s) banner.