Mewtwo can now be found and fought in Max Raid Battles in Pokemon Sword and Shield. Unfortunately there's a bit of a catch: you can't actually capture Mewtwo after the fight.
Normally, you'd be able to catch any Pokemon you manage to defeat in a Max Raid Battle. But with Mewtwo, you'll be rewarded with a number of items for defeating the creature instead of being able to capture it, including PP Max, Ability Capsules, and more. Sad face.
Mewtwo will be sticking around until March 2. Joining Mewtwo in Max Raid Battles until then are the original Kanto region starters! You can fight and then capture Bulbasaur, Charmander, and Squirtle (the best one, obviously). Although you can capture these Pokemon unlike Mewtwo, the Kanto starters also have a chance of dropping either Toxic Orbs, Flame Orbs, or Life Orbs.
Finally, Gigantamax versions of Grimmsnarl, Kingler, Hatterene, Orbeetle, and Toxtricity will all be showing up in Max Raid Battles. There's no word on when this group of Pokemon will be sticking around until.
As of the end of January 2020, Pokemon Sword and Shield had shipped a staggering 16 million units combined. There are two hefty expansions for both games set to release later in 2020, taking us to brand new locations with new, never before seen Pokemon to capture.
In other Pokemon news, Pokemon Mystery Dungeon Rescue Team DX is set to release for the Switch next week. It's a remaster of both Rescue Team games that originally released in 2006, and you actually play the role of Pokemon themselves.