Fairy Tail is an anime series that's riddled with a wide variety of Easter eggs to give viewers a fun, hidden surprise in each episode. A vast majority of these Easter eggs are often missed, but some fans couldn't help but notice a familiar silhouette of a boy wearing a straw hat among the crowd in several episodes. After much speculation, this mysterious background character was recognized as none other than the protagonist of One Piece and Captain of the Straw Hat Pirates, Monkey D. Luffy.

It's no secret that Fairy Tail manga writer Hiro Mashima and the author of One Piece, Eiichiro Oda, are long-time friends with shared inspiration from the Dragon Ball series, authored by Akira Toriyama. Although their stories are not connected nor confirmed to be in the same universe, Mashima and Oda have many similarities between their character designs and plot lines. While the likeness between the two stories appears mostly unintentional, the authors have been known to pay homage to one another by purposely placing Easter eggs and references to the other's series throughout their own. One example of this is Luffy appearing as a not-so-hidden background character in several episodes of Fairy Tail.

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One Piece Easter Egg in Fairy Tail

Luffy's first appearance occurs during Episode 20, "Natsu and the Dragon Egg," in a flashback to Natsu Dragneel's childhood. Natsu discovers what he assumes to be a dragon's egg and decides to care for it, with help from his friend Lisanna. Later in the episode, when Natsu and his fellow guild mates are gathered around in the guild hall, the egg suddenly hatches into an adorably small, blue cat with wings named Happy. The pleasant surprise of the kitten's birth breaks the tension within the guild, and amid the celebration stands Luffy, wearing his signature straw hat, seamlessly blending in with the crowd of cheering guild members.

Again, in Episode 78, "Edolas," Luffy briefly appears in the background of a scene set in the alternate world, Edolas -- a place parallel yet opposite to Earth Land in the Fairy Tail universe. Following the disappearance of their hometown, Magnolia and all its inhabitants, Natsu, Wendy Marvell and their animal companions, Happy and Carla, set off to rescue their friends from Edolas, where they discover the parallel version of their guild. Upon entering the guild hall in Edolas, the rescue team looks around to see doppelgangers of their Earth Land guild mates, and among this crowd, browsing the job request board, is the rubber man himself, Luffy.

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One Piece Easter Egg in Fairy Tail

Although most of the Luffy Easter eggs are in low resolution and hard to catch, his appearance in the second Fairy Tail series, which debuted in 2014, was very obvious. In Episode 205, "Signal of Rebellion," Luffy is seen facing away, looking up to the sky and sighing as the sun beams down on him. This particular Easter egg was especially notable, as it occurred during the opening scene of the episode, so Luffy's distinct back profile and straw hat was the first thing viewers saw. According to some fans, some subtitled versions of the episode included the text, "[LUFFY] (Sighs)" displayed at the bottom of the screen, confirming the mysterious background character's identity.

Over the years, more and more of Luffy's guest appearances have been pointed out by fans. Whether hidden amid the guild or disguised as a carriage driver for Erza Scarlett's childhood friends, Luffy's presence in the series is just another indication of the bond shared by Mashima, Oda and fans of both series. As mentioned before, it has not been confirmed that the characters of Fairy Tail and One Piece exist in the same universe. However, it's clear that these Easter eggs are there to bring joy to those who share a love for the goofy, carefree pirate captain and the adventures of a reckless, fire-breathing mage.