Rick and Morty fans have noticed a sneaky Batman reference in the Season 3 episode "Pickle Rick." While co-creator Dan Harmon has revealed the episode was largely inspired by Breaking Bad's "4 Days Out," it also drew inspiration from the Caped Crusader.

The episode famously involves the madcap Rick turning himself into a seemingly helpless pickle and going on a bloodthirsty rampage, all while dealing with his own family issues. A highlight of the Adult Swim animated series, "Pickle Rick" also earned Rick and Morty its first Emmy Nomination for Oustanding Animated Program.

Redditor Capgunkid spotted a clever homage to a 1998 episode of Batman: The New Animated Adventures. The post-credits sequence features a Joker-esque villain called Concerto tying Rick and Morty to a piano as he prepares for his "greatest performance of all time." Distracted by Danny Trejo's Jaguar saving the day, many viewers may have overlooked the Batman reference.

The 1998 New Batman Adventures episode “Legends of the Dark Knight” depicts the Joker trying to steal priceless sheet music while the Dynamic Duo is strapped to a piano and facing a similar fate to Rick and Morty.

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Interestingly, another redditor points out that The New Batman Adventuers is actually an homage to the 1966 Batman TV series episode “The Dead Ringers,” which included a cameo by Liberace as a villain who tried to kill Batman and Robin using a hole-punching machine controlled by a piano.

Whether Harmon, co-creator Justin Roiland and writer Jessica Gao were referencing either The New Batman Adventures or the live-action Batman, the Easter egg is definitely there.

Roiland has repeatedly said how much of a fan of the Dark Knight he is, and with another 70 episodes of Rick and Morty already ordered, there could be plenty more references to Gotham City's savior in the future.

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For anyone who sticks around for the Rick and Morty post-credits scenes, they'll know the frequently missed sequences have clever nods to a larger Rick and Morty-verse and have even included the return of fan-favorite Mr. Poopybutthole.

Considering "Pickle Rick" has been out for nearly a year, it might spark some viewers to go back and look at other episodes to see what they may have missed in the rest of Rick and Morty. Season 4 has already entered production, so let's hope there isn't a repeat of that supersized wait between Season 2 and 3 before this dynamic duo is back on TV