Tracey Sketchit owns a Marill, which debuted in The Crystal Onix.
Lyra owns a Marill, which debuted in An Egg Scramble!.
A Marill with the ability to Sing appeared in Pikachu's Exploration Club, Pikachu's Ice Adventure, Pikachu's Big Sparking Search, and Pikachu's Big Mysterious Adventure. This Marill would frequently sing, causing Meowth and Team Rocket's other Pokémon to go to sleep, which would make it angry and puff up, much like Jigglypuff's role.
Marill debuted in Pikachu's Vacation. It was causing trouble for Pikachu and co. along with a Raichu, a Snubbull, and a Cubone.
Wilhomena's Marill appeared in For Crying Out Loud. This one was a bit of a crybaby and it got lost in a forest with Misty.
Trixie has a Marill, which is used in her circus in Love, Totodile Style.
Pietra has a Marill, which she used to battle and ultimately capture a Rhydon that knew Surf in order to help her with her digging project.
Lola has a Marill, which she used against Flint's Golem in a battle for the title of Gym Leader of the Pewter Gym in A Family That Battles Together Stays Together!. It won after using the waves of the water to Surf against Golem.
Vivi Winstrate owns a Marill. When Vivi battled against Max in Candid Camerupt, Max wanted to go easy on Vivi's Marill, but Ash's Corphish refused to abide with Max and defeated Marill anyway.
Piplup and an Elekid both fall in love with a Marill under the ownership of Lulu in Three Sides to Every Story!.
A Marill appeared in Misty's fantasy in Bye Bye Psyduck.
A Marill was one of the Pokémon seen at the Pokémon Swap Meet in Tricks of the Trade.
Five Marill were among the Pokémon competing in the Fire and Rescue Grand Prix in The Fire-ing Squad!.
A Trainer used a Marill in Hook, Line, and Stinker to aid him in the annual Seaking Catching Competition.
Two Marill appeared in Beauty and the Breeder, under the ownership of two different Pokémon Breeders. They participated in a Pokémon breeding competition.
As part of his Breeder training, Brock asked for advice from a Trainer with a Marill in Around the Whirlpool.
A Marill was seen in Octillery The Outcast, under the ownership of an unknown Trainer.
A Marill appeared in Dueling Heroes.
A Marill appeared in Team Rocket's fantasy in Nice Pryce Baby.
Several Marill were among the Pokémon seen at Professor Oak's Laboratory in Journey to the Starting Line!.
A Marill appeared in A Ruin with a View.
A Marill was used by one of the students of the Pokémon Trainers' School in Gonna Rule The School!.
A Marill appeared in Abandon Ship!, living on the ship and bouncing past the group with two Azurill.
A Marill appeared in The Saffron Con as a Pokémon owned by a Coordinator competing in the Saffron Contest.
A Marill, along with an Azurill and Azumarill, made a cameo in the beginning of Pokémon Ranger and the Temple of the Sea, under the control of Solana's Capture Styler where they put out a fire in a forest.
A Marill appeared in The Rise of Darkrai, along with an Azumarill and Azurill.
A Marill appeared in One Team, Two Team, Red Team, Blue Team!.
A Marill appeared in Another One Gabites the Dust!, where it was seen participating in the Performance Stage of the Chocovine Contest.
A Marill appeared in Sticking With Who You Know!.
A Marill appeared in The Fleeing Tower of Sunyshore!.
A Marill made a brief appearance in Coming Full-Festival Circle!.
A Marill made a very brief appearance in League Unleashed!.
A Marill appeared alongside an Azurill and Azumarill in Zoroark: Master of Illusions.
A Trainer's Marill appeared in Curtain Up, Unova League! and Lost at the League!.
A Marill appeared in Mewtwo — Prologue to Awakening.
Marill has made cameo appearances in Kalos, Where Dreams and Adventures Begin!, A Blustery Santalune Gym Battle!, Awakening the Sleeping Giant, Going for the Gold!, A Battle by Any Other Name!, The Bonds of Evolution!, Heroes - Friends and Faux Alike!, Dreaming a Performer's Dream!, and A Fashionable Battle!.
A Marill appeared in Lumiose City Pursuit!, Mega-Mega Meowth Madness!, Day Three Blockbusters!, Battling With a Clean Slate! and even in a flashback in Mega Evolution Special I, and Garchomp's Mega Bond! at Professor Sycamore's lab.
Two Marill appeared in A Jolting Switcheroo!.
A Marill appeared in a flashback/fantasy in The Forest Champion!.
A Trainer's Marill appeared in Foggy Pokémon Orienteering!.
A Marill appeared in the book Bonnie was reading in The Clumsy Crier Quiets the Chaos!.
A Marill appeared in A Showcase Debut!, under the ownership of a Pokémon Performer participating in the Coumarine City Pokémon Showcase.
A Trainer's Marill appeared in a video in Rivals: Today and Tomorrow!.
A Marill appeared in Hoopa — The Mischief Pokémon.
A Trainer's Marill appeared in Performing with Fiery Charm!.
Four Marill appeared in Pikachu and the Pokémon Music Squad.
A Trainer's Marill appeared in Adventures in Running Errands!, where Chespin saw it riding on a bike with its Trainer while falling in love, but then Bunnelby grabs its paw while chasing Marill and its Trainer.
A Trainer's Marill appeared in A Performance Pop Quiz!.
A Marill appeared in Party Dancecapades!, under the ownership of a Pokémon Performer attending Monsieur Pierre's dance party.
A Trainer's Marill appeared in Master Class is in Session!.
A wild Marill appeared in Volcanion and the Mechanical Marvel, where it was one of the Pokémon residing at Nebel Plateau.
A Marill appeared in Valuable Experience for All!, under the ownership of a Trainer.
A Marill appeared during a flashback in The Legend of X, Y, and Z!.
| Original series entries continue below.
|| Ash's Pokédex
|| Marill, the Water Mouse Pokémon. Its sensitive ears can detect distant sounds and the round rubbery tip on its tail can expand and contract, assisting Marill in the water.
| This concludes the entries from the original series.
|| Dawn's Pokédex
|| Marill, the Aqua Mouse Pokémon. The tip of its tail floats in water, so it can swim in any current no matter how rough.
|| Dawn's Pokédex
|| Marill, the Aqua Mouse Pokémon. Its floating tail allows it to remain steady against the strongest of water currents.
| This concludes the entries from the Diamond & Pearl series.