Cloyster

Using Cloyster in a Playthrough

The Shellder line develops into Cloyster, a Water/Ice Pokemon defined by enormous physical Defense and strong offensive potential. Its 180 Defense allows Cloyster to withstand physical attacks exceptionally well, while Water and Ice STAB provide valuable coverage, particularly against Ground-, Flying-, and Dragon-type opponents. Its Special Defense is extremely poor, however, making strong special attacks dangerous regardless of its impressive physical durability. From Generation V onward, Shell Smash greatly increases Cloyster's offensive ceiling, and Skill Link makes multi-hit attacks such as Icicle Spear consistently powerful; Water Stone evolution can also require some move-planning depending on the game.

Cloyster in Competitive Pokémon

Cloyster's modern competitive identity is built primarily around Shell Smash and Skill Link. Shell Smash sharply raises its Attack, Special Attack, and Speed at the cost of defensive reductions, while Skill Link guarantees the maximum number of hits from moves such as Icicle Spear and Rock Blast, allowing Cloyster to become a dangerous sweeper after a single setup turn. Its enormous physical Defense can create setup opportunities against physical attackers and also historically supported more defensive or hazard-oriented roles before Shell Smash became central to its identity. Extremely low Special Defense remains its largest structural weakness, allowing strong special attackers and priority or revenge-killing strategies to stop it even after setup.

Cloyster in Nuzlockes

Cloyster has unusually polarized Nuzlocke value because its physical Defense is exceptional while its Special Defense is extremely poor. Against known physical attackers it can function as one of the safest available switches, and its Ice STAB can be valuable against Dragon-heavy late-game battles, but special Electric-, Grass-, Fire-, or other strong neutral attacks can be far more dangerous than its overall Defense might suggest. FireRed and LeafGreen community discussion consequently rates it as useful but matchup-dependent rather than universally safe. In later generations Shell Smash provides enormous sweeping potential, but lowering Cloyster's defenses in a permadeath format introduces additional risk if the intended sweep fails.

Cloyster is enclosed within two layers of shell, with an outer shell and spikes described as harder than diamond and durable enough to withstand extreme explosive force. Once Cloyster closes completely, its shell cannot normally be forced open from the outside. It can launch its spikes in rapid succession while remaining sealed and uses the same basic system for movement by drawing in seawater and ejecting it behind itself as jet propulsion. Wild Cloyster live around rocky sea floors and coral but have also been documented leaving the water to hunt Slowpoke tails.