Shellder

Shellder (シェルダー Shellder) is a -Type Pokémon, and can evolve into Cloyster by use of a Water Stone.

Appearance
Shellder is protected by its two large shells. Its large tongue is always kept hanging out. It has two large eyes inside the shell.

Special Abilities
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.

Locations
To get one in Red and Blue, it can be found while fishing in Vermillion City, Cinnabar Island, and Seafoam Islands.

To get one in Yellow, it can be found while fishing on routes 16 and 17.

To get one in Gold, Silver, and Crystal, it can be found while fishing in Olivine City, Vermillion City, Cinnabar Island, and Seafoam Islands.

To get one in Ruby, Sapphire, Emerald, LeafGreen, and Colosseum, it has to be traded from either FireRed or XD.

To get one in FireRed, it can be found on Route 25, Cinnabar Island, Icefall Cave, Lavender Town, One Island, Pallet Town, and SS Anne, all while fishing.

To get one in XD, it has to be snagged from Cipher Peon Gorog in Cipher Key Lair.

To get one in Diamond, Pearl, and Platinum, it can be found while fishing with the Super Rod on route 205-South, Valley Windworks, and Fuego Ironworks.