Abomasnow

Abomasnow is a unique Pokemon due to its signature ability in Snow Warning allowing it to summon hail upon entry and therefore progressively wear down the wide majority of Pokemon in the metagame, including the omnipresent Steel-types, which can be a huge asset for teams that capitalize on residual damage. Its unique Ice / Grass typing further expands its utility by making it one of the most reliable answers to bulky Water-types such as Suicune, Starmie, Swampert, Milotic, and Empoleon. Furthermore, while Abomasnow's offensive stats are nothing to write home about, it can make up for that thanks to its powerful STAB attack in Wood Hammer, a very useful priority Ice Shard, and a perfectly accurate Blizzard under hail, which can turn it into an offensive threat.

Unfortunately, Abomasnow's unimpressive defensive stats and lackluster Speed coupled with its crippling weaknesses to Steel, Fire, Fighting, Rock, and Bug leave it vulnerable to a plethora of metagame staples such as Jirachi, Tyranitar, Heatran, Infernape, and Metagross. The lack of a reliable recovery move and Stealth Rock weakness further cut into Abomasnow's survivability. While hail support can be extremely useful, it is a double-edged sword because it also wears down Abomasnow's teammates over time, since they're unlikely to have an Ice typing themselves to fully take advantage of it. As a result, Abomasnow usually needs a considerable amount of support and therefore is difficult to fit onto a team.