Lapras

With a huge 130 base HP stat, decent stats all around, an excellent offensive movepool coverage-wise, and a great ability in Water Absorb, Lapras looks awesome in theory. However, it has major issues in practice. First of all, Lapras is outclassed by other OU Water-types, notably Vaporeon (who also has Water Absorb), Milotic, and Swampert, in the role of bulky Water. This is because many of the Pokemon that bulky Waters typically check, such as Tyranitar and Metagross, beat Lapras one-on-one due to its irksome secondary Ice typing, which gives it many qualities undesirable in a bulky Water, most notably a weakness to Rock and a neutrality to Steel. In addition, Lapras is outclassed as a Dragon Dance sweeper by other Pokemon with higher offensive stats, physical STAB, and a better physical movepool, such as Salamence. Finally, Lapras is outclassed as an all-purpose special wall by the likes of Regice due to the fact that Lapras has two special weaknesses to common attacking types, namely Electric and Grass, and is also vulnerable to all forms of passive damage and status.

In general, Lapras works best against teams that rely on defensive type synergy and resistances, as opposed to those that rely on dedicated special walls to counter special attackers. Lapras has one major niche in OU: Toxic enables it stall out bulky Waters such as Milotic, and Roar enables it to phaze boosting Waters such as Suicune, and rack up Spikes damage as well. However, note that if it lacks Roar, Lapras is a poor answer to Suicune, as Suicune will then be able to Pressure stall it with ease.