- Voice actor: Kayzie Rogers (both English and Japanese)
Marill is a small,bipedal, blue mammalian Pokémon. It has a nearly spherical shape with a white underside, and round ears with red insides. Its arms and feet are short and possess no visible digits. It also possesses a zigzagging black tail with a blue, bubble-like ball on the end of it. The tail's jagged appearance originally led people to believe that it was related to Pikachu. Marill's tail is flexible and configured to stretch. Its height is 1'04" and weight is 18.7 lbs.
Aside from being able to swim well, it also has excellent hearing. It has water-repellent fur that allows it ease of swimming and reduces friction with the water. The end of its tail, which contains oil that is lighter than water, keeps Marill afloat.
Its tail can be seen bobbing on the water's surface while Marill dives underwater to feed on aquatic plants. When fishing for food at the edge of a fast-running stream, Marill wraps its tail around the trunk of a tree. Although the behavior of bouncing on its tail is more commonly noticed by its pre-evolution, Azurill, as evidenced by the episode Abandon Ship! Marill may also do this on occasion.
This Pokémon is normally found in and around fresh water.
- Main article: Pokémon food
Marill is a herbivore. Its diet mainly includes water grasses on riverbeds.
Tracey Sketchit owns a Marill of his own.
Lyra also owns a Marill.
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 sleep, which would make it angry and puff up, much like Jigglypuff's role.
A Marill was seen in Octillery The Outcast, under the ownership of an unknown Trainer.
A Marill appeared in Dueling Heroes.
Lola has a Marill which she used it 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.
A Marill appeared in A Ruin with a View.
A Marill appeared in Abandon Ship!, living on the ship and bouncing past the group with two Azurill.
A Marill along with an Azurill and an 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 One Team, Two Team, Red Team, Blue Team!.
A Marill appeared in Another One Gabites the Dust!.
Another Marill appeared in Sticking With Who You Know!.
Another 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 in Zoroark: Master of Illusions.
Marill, Aqua Mouse Pokémon. The evolved form of Azurill. Its sensitive ears can detect distant sounds and the round rubbery tip on its tail can expand and contract, assisting Marill in the water, so it can swim in any current and remain steady against the strongest of water currents no matter how rough.