Mamoswine

Mamoswine's primary role in OU is as a wallbreaker due to its high Attack stat and fantastic Ice- and Ground-type STAB combination that is very difficult to deal with defensively. It also has good utility due to its priority Ice Shard, threatening prevalent Pokemon such as Landorus-T and Garchomp. Access to Stealth Rock and its Ground typing are some of the main traits that help it fit onto teams, as both are invaluable. However, Mamoswine suffers competition from other Stealth Rock setters and Ground-type wallbreakers such as Landorus-T and Garchomp due to its mediocre Speed stat and subpar defenses, leaving it vulnerable to a lot of offensive Pokemon. Inability to reliably beat common priority users like Ash-Greninja and Mega Scizor further worsens Mamoswine's Speed issues. Overall, Mamoswine is a decent Pokemon but requires more team support than the most common Ground-types in the tier.