Abomasnow

Mega Abomasnow is a powerful wallbreaker when paired with a dedicated Trick Room team. Its low base Speed and solid base stats across the board allow it to take advantage the decent offensive coverage provided to it by its Ice / Grass typing. In addition, Abomasnow outslows and strongly damages Amoonguss, which can otherwise be annoying to many Trick Room teams. However, Abomasnow’s STAB coverage leaves it completely walled by Steel- and Fire-types like Mega Metagross and Incineroar, and such threats are nearly guaranteed to be on every team. For an archetype like Trick Room where taking advantage of limited turns is essential for success, being walled by various threats makes Abomasnow a fairly niche pick. Additionally, a Grass / Ice typing leaves Abomasnow with seven weaknesses, including a crippling weakness to incredibly common Fire-type moves. As a result, Abomasnow needs Trick Room up, because otherwise it's quite likely that a foe will be able to take advantage of its low Speed and hit it with a super effective attack.