Over the past few years of Pokémon Go, dataminers have been pretty reliable at finding out about new in game creatures before they're officially made available. That trend today continues, as we've just learned about a handful of new creatures coming soon to the game.
Dataminers over at The Silph Road dug through game files, and found sprites for regular and shiny forms of Smeargle, Celebi, Jirachi, Clampearl, Huntail, Nincada, Ninjask, Shedinja, as well as four different forms of Deoxys.
Celebi being added to the game was already known before this datamine. People attending the Pokémon Go Fest 2018 in Chicago this weekend will be able to complete a special research task to attain the creature, with players elsewhere in the world able to complete a special research quest shortly afterwards to earn it.
It's not confirmed, but it's entirely possible we will learn more about these other new additions to the game during Go Fest at the weekend.