To celebrate the new Pokémon the Movie: Secrets of the Jungle, Niantic is introducing a themed event to Pokémon GO. Fan-favorite characters Jessie and James are returning for the event, but that's only the beginning of the excitement.

Trainers can also look forward to lots of in-game content inspired by Secrets of the Jungle, ranging from new Pokémon to themed items. Jessie and James will guide players through the themed Special Research, instead of Professor Willow, where players can encounter a Shiny Celebi.

Plus, Jessie and James' Meowth balloon will appear more frequently on Dec. 25 from 8 a.m. to 10 p.m. local time and players can pick up avatar items inspired by Jessie's and James' outfits from Secrets of the Jungle for free in the Style Shop.

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Explorer Pikachu makes its Pokémon GO debut to celebrate Secrets of the Jungle

Shiny Celebi isn't the only special Pokémon joining the game for this event. Explorer Pikachu makes its Pokémon GO debut on Dec. 14 at 8 a.m. local time, and will appear in the wild and in raids until Dec. 21 at 10 p.m. local time. If players are lucky, they might even encounter a Shiny Explorer Pikachu. Trainers who take a snapshot during this time may see Jessie and James appear.

During Pokémon Spotlight Hour on Dec. 15 from 6-7 p.m. local time, Explorer Pikachu will appear more frequently in the wild and players will receive double Candy for catching Pokémon.

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Players will also encounter certain Pokémon more frequently during the Secrets of the Jungle event. Until Dec. 17 at 10 p.m. local time, Hoothoot, Nuzleaf, Drilbur, Cottonee, Dwebble and more will appear more frequently in the wild. Players might even encounter a Durant, with Lickitung, Mawile, Flygon, Rufflet and more appearing in Raid Battles. Igglybuff, Smoochum, Elekid, Magby, Bonsly and Rufflet will hatch from 5km Eggs and there's a possibility for a Shiny Rufflet.

All of this content is meant to celebrate the latest Pokémon movie, which will hit theaters in Japan before the year is out. Players also have tons of Pokémon GO updates to explore throughout December, which is a jam-packed and exciting month.

Directed by Tetsuo Yajima and written by Satoshi Tajiri, Pokémon the Movie: Secrets of the Jungle will be released Dec. 25 in Japan and will be released in 2021 in the U.S. It is the 23rd film in the Pokémon Universe and the first in the Generation VIII Series. Players can celebrate its release in Pokémon GO starting Monday, Dec. 14 at 8 a.m. local time.

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