Bulbasaur and Squirtle aren’t the only starters you can find in Pokémon Sword and Shield’s Isle of Armor expansion. All three Alolan Starter Pokémon are obtainable, but you will need to put in quite a bit of work to get just one of them.
There is only one way to get the Alolan starters in Sword and Shield, and that is by participating in the Alolan Diglett search quest.
Related: All 150 Alolan Diglett locations and rewards in Pokémon Sword and Shield’s Isle of Armor expansion
There are 150 Alolan Diglett hidden around the Isle of Armor, with some areas of the map housing up to 20 of the Mole Pokémon in various spots. There are milestones you can hit within this side quest that will give you special rewards, mostly Alolan Pokémon with their Hidden Abilities, and this includes the starters.
You can find most of them by simply traveling around the new Wild Area, but to get Litten, Rowlet, or Popplio, you will need to find a majority of them. Once you send 100 Diglett back to their trainer you can head back to the NPC and he will give you one of the starters, with their Hidden Ability unlocked.
You can only claim one of these gifts, however, it will automatically be decided based on which Galar Starter you picked at the beginning of your journey.
100 Diglett: Alolan Starter – Hidden Ability
Rowlet (Grookey Chosen) – Hidden Ability Long Reach
That means you will need to find other ways to collect the remaining two starters, whether that be by finding a friend who is willing to trade them to you, or simply by transferring them over in Pokémon Home.