0031 Nidoqueen

Poison Jab is the fast move of choice due to STAB and much higher energy gains. Bite deals strong Dark-type damage, but lacks STAB and energy gains. 

Poison Fang is all but mandatory on Nidoqueen, functioning as both a strong bait move and a powerful spammy option in its own right. Earth Power helps Nidoqueen access a Ground-type charge move sooner, while Stone Edge provides wide coverage. Since both Earth Power and Stone Edge cost the same energy, Nidoqueen doesn't need to shield bait. Sludge Wave or Earthquake could be chosen as harder-hitting options, but the cost of 10 more energy risks Nidoqueen fainting before being able to use them.

Poison Fang completely changed Nidoqueen, taking it from a meme-y spice pick to an incredibly relevant one. It has a number of relevant wins with only Poison Jab + Poison Fang, and it has Earth Power to take on some of the format's powerful Steel-types. The Shadow version is preferred over the normal version due to an improved matchup against Azumarill and Galarian Stunfisk, among other things. However, if you don't have a Shadow ready, the normal is a perfectly serviceable option.

Normal Nidoqueen outperforms its Shadow sister in Ultra League. While you won't see it much in Open Ultra due to the overwhelming prevalence of Giratina and Cresselia, it has a fair bit of play in the Premier format! Not only is it a fantastic anti-Charm option, it also has a lot of play against some Fighting- and Grass-types running around the format!

For what it's worth, Nidoqueen does have a niche of being one of the best counters to Zacian in the game thanks to its rare combination of resistances to Play Rough, Close Combat, and Wild Charge. It can also taken on Togekiss, and access to Stone Edge and Earth Power lets it threaten Ho-Oh and Dialga. These are all awesome qualities, but Nidoqueen's stats are too low for it to be more than a spice pick.