The frosty creature, Kyurem, has returned to Emera Town and stays until February 17th. As always, it is searching for trainers who express their love for Pokémon by interacting a lot. Every interaction you do gives you a random chance of encountering Kyurem. Plus, as a special incentive for every trainer who has already met it before: The probability of receiving a shiny gift from Kyurem has been further increased this year!
Check out the forum news post (from 2020) linked below for a detailed description of the event and an FAQ.