The "8th Anniversary Party" event is a costume-heavy celebration that runs between Friday, June 28 at 10.00 and Wednesday 3 July at 20:00 local time in Pokémon Go.

The main event is the debut of party hat-wearing Grimer and Muk – who join Pikachu, Eevee and Kanto starters with their own headdresses, who also make an appearance – as well as the return of shiny Meltan (who is otherwise shiny locked out by events.)

In addition to free and premium Timed Research tasks, there's the debut of "Whispers in the Woods" Masterwork Research, as well as a new event bonus and a set of wild Pokémon spawn every other day.

There's a lot going on, in other words—and this "8th Anniversary Party" event guide can help explain what to expect and when to expect it.