In outfits in Pokémon Legends: Arceus.
To complete the quest, players will need to find the two varieties of the sea slug Pokémon Shellos. The West Sea Shellos is bright pink and white, and it can be found in two regions in the Southern Obsidian Fieldlands, Sandgem Flats and Ramanas Island. In addition to Shellos, players will also have the opportunity to catch its evolved form, West Sea Gastrodon, at the aforementioned locations. Like Shellos, Gastroden has different colors for the East and West Sea variants.
Of note, an Alpha Snorlax roams this area, so players should proceed with caution while searching for the sea slug Pokémon. Players may want to use their Wyrdeer mount Pokémon to speed away if the Alpha Snorlax spots them. Additionally, there is a chance for a mass outbreak in Pokémon Legends: Arceus of West Sea Shellos in Obsidian Fieldlands, which will cause a large amount of the Pokémon to appear and notably increase a player's chance to find a shiny one.
Finding East Sea Shellos for Request 45 in Pokémon Legends: Arceus
The brightly colored blue and green Shellos in the East Sea can be found by traveling to the Cobalt Coastlands and heading to either Tranquility Cove or to Seagrass Haven. However, to find the Water-type sea slug, players will need to use their Basculegion mount. Accordingly, the green and blue East Sea Shellos are the harder of the two variants to find and require players to have progressed further in the game to unlock the surfing mount Pokémon in Pokémon Legends: Arceus.
Players will not only need to find these two Shellos to complete the quest, but they will need to catch them and them to their Pokédex. To capture these Pokémon, players may want to approach cautiously and throw a berry to distract them before throwing a Poké Ball. Generally, Shellos are fairly easy to catch with a docile nature, and they typically appear at a lower level. Because Shellos have a high spawn rate, players should easily be able to find another if they miss an attempt to catch the colorful sea slug Pokémon. Players may even find a shiny in Pokémon Legends: Arceus with some luck.
Once players have successfully caught both the blue and green East Sea Shellos and the pink and white West Sea Shellos, they should return to Jubilife Village and show both to Anthe to complete the quest "Request 45: Shellos of the East and West" and receive their next quest. Completing this questline will also unlock more clothing options at the Clothier in Jubilife Village.
Pokémon Legends: Arceus is available for Nintendo Switch.
