Mamoswine

Mamoswine is the most powerful Ground-type in the UnderUsed metagame, with an absolutely astounding base 130 Attack. Its typing comes as an offensive blessing and a defensive curse; Ice-type attacks are a huge bane to the UnderUsed tier, and Mamoswine makes perfect use of these weapons. Additionally, its Ground-typing grants Mamoswine near-perfect STAB coverage, allowing it to take down the majority of Fire- and Steel-types. Ice Shard is an extremely useful priority move, as it hits a lot of top threats super effectively and is backed up by Mamoswine's insane power. Mamoswine's power is so dependable that it can get away with running Focus Sash, allowing it to contribute as an effective lead, especially due to its access to Stealth Rock, Endeavor, and Ice Shard to get past other suicide leads. It is important to note that most of Mamoswine's drawbacks lie in its mediocre Speed and, more importantly, its poor defensive typing, providing it with a total of zero useful resistances and making it difficult to bring into the field. Furthermore, many faster Pokemon or priority users easily take advantage of Mamoswine if it is weakened, especially if they're not weak to Ice Shard.