Given the mangaka's unpredictable nature, One Piece fans have often had a difficult time correctly guessing Eiichiro Oda.
In all fairness, they don't always get it wrong. Many readers had even figured out that Pudding was secretly evil during the Whole Cake Island. With that said, Oda loves to foreshadow events from the future in the current storyline. It's no surprise that so many theorists would look for meaning in the wrong places. But surprisingly, some of these popular theories made sense back then. However, a few of them were considered bonkers after the theories were debunked.
Readers must take into account that there will be a few manga spoilers throughout this article. Therefore, they are asked to reconsider before proceeding with their reading.
Disclaimer: This article reflects the writer's personal views. All external media in this article are the property of their respective owners and Sportskeeda claims no ownership of the same.
Here's a retrospective look at debunked One Piece theories that used to be popular
10) Queen's Devil Fruit was related to ancient scorpions
The strongest members of the Beasts Pirates follow a specific pattern since most of them have consumed Ancient Zoan Devil Fruits. In the One Piece series, Queen was the last All-Star to reveal his fruit.
It was commonly predicted that his Devil Fruit would be related to eurypterids, the ancient scorpions of the sea. The reason lies within his penchant for deadly viruses. The Queen also had a hairstyle that greatly resembled a scorpion tail.
Eventually, it was revealed that Queen ate the Ryu Ryu no Mi, Model: Brachiosaurus. But it came as a surprise to the fandom to think that most of the fans would have wrongly predicted this information.
9) Akainu’s Devil Fruit would be related to blood
When the Admirals finally worked alongside each other in Marineford, readers tried to speculate what Akain's powers could be. Aokiji and Kizaru both had Logia Devil Fruits, so it was only natural that he would follow suit.
Due to his murderous rage and red color scheme, some people thought Akainu would have a blood Logia. Ideally, it would have been a perfect fit for his extremist belief in "Absolute Justice," considering how many lives he took back in the Ohara incident.
In reality, he consumed the Magu Magu no Mi, which gave him the power of magma. The vast majority of Logia fruits are inspired by natural elements, which should've disconfirmed the blood theory before Marineford.
8) Big Mom’s Devil Fruit would be related to acid
When she first showed up on Fishman Island, the monstrous Big Mom was mostly seen in the shadows. The corrosive drool coming out of her mouth started melting the floor beneath her.
This led many readers to believe that her Devil Fruit was acidic in nature. Even in the strange world of the One Piece series, not many characters have caustic saliva. Needless to say, this was a very unusual occurrence.
Of course, it turned out that Big Mom was simply very hungry. Her Devil Fruit is the Soru Soru no Mi, which gave her the soul manipulation powers.
7) Sanji’s father was a member of the Five Elders
Even before the One Piece timeskip, some readers speculated that Sanji had royal blood. The series even left behind many clues to boggle its readers, such as his "Mr. Prince" alias in the Alabasta saga. Despite living in the East Blue, it was revealed that he was not born there.
Shortly before the Whole Cake Island arc, it was shown that Sanji's bounty poster wanted him alive. More than a few people believed that he could've been related to a blonde member of the Five Elders, simply because of vague similarities in their appearances.
With the appearance of Vinsmoke Judge, this peculiar theory was laid to rest. Meanwhile, the blonde elder's identity is yet to be confirmed. In this regard, it is interesting to note that none of the Five Elders seem to have eyebrows, unlike Sanji and his trademark swirl.
6) Yamato's Devil Fruit could turn him into a White Tiger
Prior to his fight with Kaido on the Skull Dome rooftop, Yamato was shown using his Devil Fruit powers. There was a single instance where his teeth had turned into sharp canines towards Sasaki, but that didn't last very long.
One Piece fans tried speculating on the possibility of a Zoan fruit which should be related to the feline's presence. Byakko was a popular suggestion, since they it is a mythological white tiger from Japanese folklore.
Theorists were somewhat close, but they got the wrong animal. Yamato ate the Inu Inu no Mi, Model: Okuchi no Makami. The powers granted by the fruit enabled the user to turn them into an ancient wolf instead of a great white tiger.
5) Kaido was a dragon who ate a Hito Hito no Mi
Kaido used to be known as the "world's strongest creature." Although he could turn into a dragon with his Devil Fruit, that form seemed much weaker than his regular human one. For that reason, some One Piece readers thought he was born a dragon but consumed a human fruit.
During the Onigashima Raid, it was revealed that Big Mom gave Kaido his Devil Fruit during the God Valley incident. It was at this point that Kaido also had a flashback of his younger days. While not much was revealed, it became clear that he wasn't born a dragon.
An intriguing fact about the One Piece series is that the oni race still remains a huge mystery. On that note, fans should remember that Kaido's strange appearance in the franchise is what led many to this speculation in the first place.
4) Ryokugyu is a good person
Prior to his official introduction, many readers believed that Ryokugyu would adhere to a strict moral code. Now, we are talking about a character his who blatantly defied Akainu's orders to arrest Fujitora at the Levely.
When he flew to Wano Country using a flower, it was speculated that he would turn the industrial wasteland into a luscious forest. However, it became clear that Ryokugyu did not possess any ability to create and control plants.
Of course, One Piece fans know better now. But for those who are new to the series, believe it or not, Ryokugyu is somehow worse than Akainu. The crazed lunatic not only praised the Celestial Dragons, he also wanted to kill as many civilians as possible.
3) Carrot is the traitor
For the longest time, One Piece readers knew there was a traitor among the alliance members. Somebody was feeding the Beasts Pirates crucial information. While many readers correctly suspected Kanjuro, there had been some unconventional picks from the community.
Carrot was a popular choice for these traitor theories. Keep in mind that somebody gave Jack a Vivre Card, which led him to Zou where he fought the Mink Tribe and looked for Raizo. It would make sense for somebody in that region to have a Vivre Card. They would also have to know that the Red Scabbards are still alive.
Carrot happened to meet some of these requirements, which is why she was suspected of being a traitor. In hindsight, this One Piece theory only made sense because it justifed her lack of screentime.
2) Zoro kills Kaido (ZKK theory)
Roronoa Zoro has a very dedicated fanbase within the One Piece community. Despite his fierce loyalty to his captain, many of his ardent followers put him on equal footing with Luffy, much like the relationship shared between Naruto and Sasuke.
Some theorists argued that Zoro would be the one to finish off Kaido for multiple reasons. Thematically, he was linked to Shimotsuki Ryuma, a powerful samurai who cut off a dragon's head before. Typical of a shonen hero, Luffy didn't kill anyone throughout the One Piece series, yet Kaido's death was something that was expected. By the end of the Onigashima Raid, Oda maintained the One Piece status quo. Therefore, as Luffy defeated Kaido, Zoro took care of King.
1) The raid would fail
Although the raid theory was fairly prevalent before, much of the credit for popularizing it goes to YouTuber Mr Morj. Many One Piece readers even believed that Oda needed to raise the stakes for the Wano Country arc.
Remember, this would be Luffy's first serious attempt at fighting a Yonko. The idea was that Kaido and the Beasts Pirates would defeat the alliance at Onigashima. Afterwards, the Straw Hats and their allies would escape their capture, and they would try the same thing again in the Flower Capital.
This was a widely polarizing theory simply because readers felt Wano Country was already too long. Of course, the raid was a complete success. Although Luffy did suffer a few minor defeats, he eventually put down Kaido for good.
While more and more theories pop up on several sites every day, it is hard to keep track of each one of them, unless they become insanely popular. But let us know which among these theories you believed in before they were debunked by the mangaka for good.