Marius spotted Max as he was trying to climb the wall of the closed museum. As a result, he assumed that Ash and Max were trying to break in because they were thieves. At this, Marius sent out his Spheal to attack them, not listening to their repeated denials. However, Spheal wasn't interested in battling and only wanted to play. Pikachu quickly defeated Spheal with a single Thunderbolt, leaving Marius speechless. Max then explained Water-types are weak against Electric-type moves.
Soon, Captain Stern arrived, and Marius promptly told him Ash and Max were thieves. Max then explained that he just wanted to see the museum. After dealing with the misunderstanding, Captain Stern invited them all in to see the museum. Marius displayed his lack of knowledge about Pokémon during the tour, where he declared that he wanted to catch a Goldeen so it could evolve into a Gyarados. Max then corrected him, saying only Magikarp evolve into Gyarados. Marius also dreamed about traveling around the world by sea inside the submarine that the Captain was building.
Marius, Ash, and Max were later captured by Team Rocket after being lured out by snow cones. They soon escaped with the help of Ash's Corphish and confronted Team Magma, who had stolen Stern's valuable rock. Captain Stern and Ash handled Team Magma while Marius and Max were ordered to get Officer Jenny. Marius and Max jumped off a steep sea cliff, while his Spheal aided the pair in reaching the police. By the time the police arrived, Team Magma fled with a portion of the stone. Afterwards, Marius informed Ash of his desire to have a rematch the next time they met.
|Spheal is Marius's only known Pokémon. He sent sent it out to deal with Ash and Max when he assumed that they were thieves. Ash used his Pikachu to battle Spheal. However, Spheal spent much of its time clapping rather than battling and was defeated easily by a single Thunderbolt. Later, Spheal repeated this behavior while Marius, Ash, and Max were stuck in Team Rocket's cage. Spheal was shown to be adept at traversing large bodies of water at very high speeds when it swam Max and Marius to the shore opposite the Oceanic Museum.|
|Debut||The Spheal of Approval|
- Marius bears a striking resemblance to the Bug Catcher Trainer class in the games. Despite this, he does not own any Bug-type Pokémon.
- Marius shares his name with another character of the day, Captain Marius. Similarly, this Marius makes the impression that he is striving to become a sea captain.
|This article is part of Project COD, a Bulbapedia project that aims to write comprehensive articles on each one-time character of the Pokémon anime.|