https://www.gamespot.com/articles/pokemon-free-legendaries-for-july-2018-available-s/1100-6460074/

The Year of Legendary Pokemon rolls on with another pair of free Legendaries for Pokemon Ultra Sun and Ultra Moon. Next month, The Pokemon Company is giving away two powerful monsters that originally appeared in Pokemon Black and White versions: Tornadus and Thundurus.

Continuing the trend of previous distributions, the Legendaries will be given out in different ways depending upon your region. US residents can pick up a free download code for the Pokemon at the electronics section of Target from July 13-28; those in Europe can download the Legendaries over the Nintendo Network via Mystery Gift from July 6-22; and players in Canada will receive a code in the Pokemon Trainer Club newsletter.