The theory of a Yellow Shellos began with fan interpretations inspired by real-world marine organisms such as the scaly-foot gastropod and various deep-sea snails. These creatures, known for their unusual coloration and adaptations, led some fans to imagine a new variant of Shellos with a yellow-toned design and possibly a different typing.
Within this idea, some players on Reddit proposed that Shellos could evolve into a more defensive, tank-like form of Gastrodon, potentially gaining a Water/Steel typing. This concept fits with how the Pokémon franchise often draws inspiration from biology while adding fantasy elements to redesign familiar species.
