In a brand new Nintendo Direct today, three returning Pokemon were revealed for Sword and Shield. The three big Legendary birds: Articuno, Moltres, and Zapdos are all arriving in the two games later in 2020.
Each Legendary has a Galarian twist, as you'd come to expect from an established Pokemon arriving in the Galar region. You can see all three Galarian Legendaries just below, all of which will be arriving in both Pokemon Sword and Shield through the two forthcoming expansions.
DLC expansions are a first for the Pokemon series, and two new expansions were revealed in the Nintendo Direct today: the Isle of Armor and the Crown Tundra. There's no word yet on which expansion the three Legendaries will be included in.
The Sword and Shield Expansion Pass, which includes both expansions, is available to purchase today for $29.99. The first DLC, the Isle of Armor, is slated for release before the end of June 2020, while the Crown Tundra releases in Fall 2020. Both expansions will take us to brand new locations, complete with wild areas and over 200 returning Pokemon from the series.
You can see the full Nintendo Direct just below, which also revealed a remake of Pokemon Mystery Dungeon. The two Mystery Dungeon games from 2006 are being remastered, and releasing as Pokemon Mystery Dungeon Rescue Team DX, in March 2020. There's a demo releasing later today, and all progress will carry over to the final game.
Additionally, Galarian Slowpoke is now available in Pokemon Sword and Shield. While it won't evolve into Galarian Slowbro until the Crown Tundra DLC releases, you can catch it right now in either version of the game.