Cloyster

The nerf to partial trapping in Stadium OU hits Cloyster quite hard, as Clamp is one of its most important tools in standard OU. Despite this, Cloyster is able to carve out a niche for itself thanks to its high Defense and immunity to freeze, allowing it to wall most common Snorlax sets. Stadium's nerf to Hyper Beam and revamped critical hit rates also make Cloyster more effective at checking Tauros. Cloyster also still has access to a powerful Explosion as well as Ice-type STAB moves that threaten freeze on foes.

Despite its robust defenses, Cloyster can get into trouble if luck does not go its way. Snorlax has a high critical hit rate in Stadium OU at 10.3%, and critical hits and full paralysis can break through Cloyster's Rest loop. Compared to Snorlax, Tauros has a higher critical hit rate at 18.1%, but Cloyster will only be hit twice before it wakes up due to Tauros being faster. Snorlax and Tauros can both use Thunderbolt to catch Cloyster off guard, making it a much less effective wall. Additionally, Cloyster is weak against other tier staples such as Starmie, Chansey, Zapdos, and Persian. The changes to Substitute's mechanics also makes Cloyster's Explosion riskier, as using Explosion on a Substitute will now knock Cloyster out. Overall, Cloyster has a strong niche in the metagame as a physical wall, but its flaws keep it from being among the top threats.