Kalos Celebration Event

Kalos Celebration Event was an event in Pokémon GO to celebrate the release of the Kalos Region. It was a part of the Pokémon GO's first Season: Season of Celebration. It was announced on the update GO Beyond.

Features
Every spin from PokéStops gave at least four Items, with high rate of Poké Balls.

Featured Pokémon
The following Pokémon were released in wild globally with the start of the event:

A region-exclusive Pokémon was introduced in France.

Following Pokémon are acquired by evolution only.

The following Raid Bosses were available for a time of this event:

Field Research event tasks
There were several Field Research tasks exclusively for the duration of the event.

Timed Research
During this event there was a Timed Research series that was titled Kalos Celebration Event in game. A total of 30 Venusaur Mega Energy, 105 Charizard Mega Energy and 30 Blastoise Mega Energy could be obtained for completing it.

Controversy
Although the officials had claimed an increase of Kalos Pokémon in the wild, many players found out the low spawn rate of them, especially the Starters. Incense did not help either. Players had expressed concern of not able to complete the Timed Research due to the absurdly low appearance of the required Pokémon, with Froakie being the most severe case. It is presumably because the extreme popularity of Froakie's final evolution - Greninja compared with the other two.