|Abilities||Shell Armor, Skill Link, Overcoat (Hidden)|
|Episode First Shown in||The Bridge Bike Gang|
|First Known Owner||Tyra|
|First Game Appeared in|
|National Dex Number||#091|
Cloyster is the Bivalve Pokemon. It is the evolved form of Shellder.
Cloyster appears to be a black pearl inside of two purple shells. There are several spikes on the shell, and one on top of Cloyster's face. Cloyster has triangular white eyes and a mouth.
- Butch's Cloyster first appeared in Enter Kost Mountain.
- Viridian Gym's Cloyster appeared in The Last Step! Part 2.
- Lorelei's Cloyster appeared in The Giant Mandarin Island!, where it battled against Scott's Growlithe and Electabuzz.
- Carr's Cloyster debuted in Vs. Cloyster.
- A Cloyster at the Virdian Gym appeared in Vs. Rhydon.
- Lorelei's Cloyster appeared in Vs. Lapras.
- A trainer's Cloyster appeared in Vs. Azumarill.
- Wild Cloyster appeared in Vs. Lanturn.
- Silver's Cloyster debuted in Vs. Silver 1.
- A Cloyster was a part of Lawrence's Collection in Desperate Call for Help.
- A coordinator's Cloyster appeared in Vs. Wartortle.
- Toxic Spikes
- Aurora Beam
- Spike Cannon
- Icicle Crash