Holiday in 2017 is the second Holiday event in Pokémon GO. Moreover, this event is connected with the release of twenty aquatic-themed, Hoenn-region Pokémon. 
Similarly to the year-before event, for the duration of the event, Lure Modules lasted for six hours before they expire.  and as a special bonus, the first PokéStop visited each day between December 22nd, 2017, at 1:00 p.m. (PST) and December 25th, 2017, at 1:00 p.m. (PST) awarded trainers with a single-use Egg Incubator.
Festive Pikachu returned with release of a Pokémon from the Johto-region, "present-bearing" Pokémon Delibird. Lapras did not appear near to water region only. These Pokémon had increased chance to appear in the wild during this event.