Cloyster @ Leftovers
Cloyster spikes up GSC OU, helping offensive teammates make progress in a very bulky metagame! Spikes wears down the opposing team and outdamages Leftovers recovery on switch in. Surf deters Rapid Spin users such as Golem and non-Giga Drain Forretress, and also hits Explosion switch-ins such as Gengar, Tyranitar, and Steelix. Toxic pressures Starmie, which tends to come in to remove Spikes, and is useful to wear down opposing Cloyster and Curse Snorlax. Explosion lets Cloyster soft-check Snorlax and trade with the opposing team after it has laid down Spikes. Cloyster's Spikes massively enables offensive teammates such as Jynx, Nidoking, Gengar, and Zapdos, as it prevents grounded answers in Snorlax and Raikou from coming in repeatedly to deal with them.