The only way to capture Pheromosa in Pokemon Sword and Shield is by purchasing the expansion pass. Buy is many players' choice. The Crown Tundra is an exclusive location to the expansion pass and the way players will be able to encounter Pheromosa.
Once this is done, players will be able to find this Pokemon in the Dynamax Adventures. In this game mode, players can team up with friends and take on multiple Dynamax battles in a row.
In the end, the player will encounter a legendary Pokemon they can capture with a 100% success rate. Now is the best time to . Continue to go through the Dynamax Adventures until the player finds Pheromosa. It may also appear as Shiny.