Today we're starting the run-down of holiday events in Pokemon GO that'll take place in the month of December, 2019. The first big change and update starts on Monday, December 16, 2019! This action begins with Pokemon eggs, and Niantic suggests that "you can expect different Pokémon to be hatching from Eggs! Which Pokémon will they be? Incubate some Eggs and start walking to find out!"