Shellder is protected by its two large shells. Its large tongue is always kept hanging out. It has two large eyes inside the shell.Shellder can have the ability Shell Armor or the ability Skill Link. Shell Armor prevents Shellder's opponents from getting a critical hit on Shellder. Skill Link increases the frequency of multi-hitting attacks. As a last resort, Shellder clamps on to its opponents. It swims backward by opening and closing its two shells.