https://www.gamespot.com/articles/aprils-free-legendary-pokemon-for-ultra-moon-and-s/1100-6458389/

Pokemon Ultra Sun and Ultra Moon players now have a chance to add another free pair of Legendaries to their teams. Beginning this weekend, The Pokemon Company is giving away Entei and Raikou as part of its ongoing Year of Legendary Pokemon celebration, but they'll only be available for a very limited time.

To claim the Legendaries, fans in the US will need to travel to a specific retailer and pick up a download code for the Pokemon. This time, the free code will be available at the electronics section of participating Target stores across the country from April 22-29. Players in Europe, meanwhile, can download the Legendaries via an online Mystery Gift from the games' main menu until April 25.