Tricky Pokémon 2021

Tricky Pokémon in 2021 was the third April Fools' Day Event in Pokémon GO.

Featured Pokémon
These Shadow Pokémon were released with the start of the event:

Tricky Pokémon had increased spawn rates in the wild and from Incense or Lure Modules:

There was also a chance of being Photobombed by either of these Pokémon up to 5 times:

Timed Research
During this event there was a Timed Research series that was titled Tricky Pokémon in game.

Trivia

 * Unlike what happened in previous year's event, shiny Aipom and Croagunk generated from this event's Photobombs did not display their shiny colors in the Map View.