Nidoqueen

Nidoqueen has found a home in OU as a surprisingly versatile Pokemon. It's a great fit on stall builds with access to both Stealth Rock and, notably, Toxic Spikes. With key resistances to Rock- and Fighting-type attacks through its Poison / Ground typing, Nidoqueen is a great defensive check to Pokemon like Breloom, Lucario, Tyranitar, and sometimes even Infernape. Over time, Nidoqueen has proven to fit very well on balanced builds and even offense, clearing Toxic Spikes on entry and setting up its own entry hazards to support its offensive teammates. Defensive Pokemon can sometimes find themselves irritated by Nidoqueen, as its typing grants it an immunity to both Thunder Wave and Toxic. On top of that, its movepool is quite vast, so it can be molded to suit a team's needs very often.

However, Nidoqueen's biggest weakness is its lack of reliable healing, meaning it gets chipped down really easily by a myriad of offensive threats and even defensive ones as well. Its base stats are underwhelming for OU, with decent defenses at best and subpar Attack, Special Attack, and Speed. While it is a great fit on stall builds, it can also be a detriment by being setup fodder for Spikes users like Skarmory and Roserade as well as setup sweepers like Calm Mind Suicune, Calm Mind Clefable, and Dragon Dance Gyarados if it doesn't have the right moveset.