After Dawn caught a Buizel, Zoey caught Gastrodon when it was a Shellos. Though somewhat shy, Shellos was close with Zoey, as it searched with Glameow help when she got injured. Zoey used it in some of her contests, including the Wallace Cup where it defeated a Mareep. Zoey later revealed that Shellos helped her win her third ribbon.
Prior to the Grand Festival, Shellos evolved into a Gastrodon and used it with Lumineon to pass the first round and then the first round of battles. Gastrodon then battled alongside Glameow in the quarterfinals to help Zoey place in the semifinals.