Nyarth, also known as Meowth, is a persistent and opportunistic character driven by the pursuit of financial gain, often through capturing rare Pokémon. In the special "Pikachu no Fushigina Fushigina Daibōken," he spots an Unknown and immediately devises a plan to seize it, believing it will bring unlimited wealth. This goal leads him, along with Sonansu and Manene, to follow the Unknown through a mysterious portal after it is led away by an Eneco. During the adventure, Nyarth pursues the Unknown with determination despite repeated setbacks. After entering the portal, he and his companions encounter a Maril that uses Sing to put them to sleep, causing them to fall and restart their journey. They experience size distortions in another realm, growing mega-sized before later being miniaturized next to a giant Pikachu. Nyarth continues his pursuit even when threatened by Pikachu's Thunderbolt, which he warns could cause permanent paralysis. His plans are frequently disrupted by external factors, including Teeter Dance from Manene and further encounters with the sleep-inducing Maril. Nyarth's interactions with other Pokémon blend aggression and inadvertent comedy, such as when he mistakes Maril's tail ball for an Oran Berry, leading to another instance of being put to sleep by Sing. The journey concludes with Deoxys rescuing the group, and Nyarth witnesses the Unknown reuniting with its kind. He returns to the city through a portal and ends the day watching a fireworks display. Beyond this special, Nyarth appears in numerous other Pokémon media, including main series episodes, movies, OVAs, and video games, consistently portrayed as a member of the Rocket Gang involved in various schemes to capture Pokémon, often motivated by financial gain.