It used to have a shell on its back long ago. This species is closely related to Pokémon like Shellder.
It oozes a purple fluid to deter enemies. Apparently, there are more West Sea Shellos now than there were in the past.
Found in abundance on seashores bordering warm waters. Shellos are unexpectedly friendly and will crawl toward any person they see. Take care not to get coated in mucus!