Region-dependent Pokemon forms have never extended to legendary Pokemon before. However, some new concept art revealed in the recent Pokemon Direct makes it seem like Pokemon Sword and Shield will end that trend soon.
There are three pieces of Pokemon Sword and Shield art that each depict one of the three new Pokemon. These Pokemon are bird-like in appearance and bare very strong and striking resemblances to the three legendary bird Pokemon of the Kanto region: Articuno, Zapdos, and Moltres. Of course, the design of the birds in the artwork does look different from the birds of Kanto, and because the Direct didn't officially confirm this art depicts Kanto's legendary bird trio, claiming it does is speculation (albeit with some solid evidence).
With that out of the way, the design of each bird bears a distinctive feature to its corresponding counterpart. The bird that looks like Galarian Articuno has the same silk-like tail that the original Articuno has. The bird that looks like Moltres has the same flaming plumage of the original Moltres, and the bird that looks like Zapdos has the same spiked-feather appearance; although, unlike the original Zapdos, it has a much beefier set of legs.
The artwork comes with a reveal that legendary Pokemon will be returning from every generation. While the Direct didn't specify if every previous legendary would be making a return, it very heavily implied it. And while it neglected to show the bird trio with the other Kanto legendaries, this new concept art suggests they'll be returning, too, just in different forms.
If that does turn out to be the case, the bird's new Galar forms look like they'll grant them new typings and abilities. Galarian Articuno's art shows it shooting lasers from its eyes. Galarian Moltres looks like it might be a Dark and Fire-type, and Galarian Zapdos' new ostrich design makes it look like it forewent its Flying typing for something like Fighting.
The slew of returning legendary Pokemon, including these three mysterious bird Pokemon, will arrive with The Crown Tundra expansion, which will release this fall as the second of a two-part DLC series for Sword and Shield. It, along with The Isle of Armor expansion, will bring back old Pokemon that didn't make it into the vanilla version of the game, in addition to new Pokemon forms.
Pokemon Sword and Shield are available now for the Nintendo Switch.