If you like circular blue rodents, Happy Mother's Day! Niantic has announced Marill Limited Research Day for Sunday, May 9th from 8 AM – 10 PM local time. Let's get into the details.
Here's what the official Pokémon GO blog had to say about Marill Limited Research Day:
As Fairy-type Pokémon continue to appear more often in the wild during the Luminous Legends X event, you can look forward to a Limited Research event featuring the Water- and Fairy-type Pokémon Marill! On Sunday, May 9, 2021, from 8:00 a.m. to 10:00 p.m. local time, you can complete event-exclusive Timed Research tasks that lead to encounters with Marill. If you're lucky, you might even encounter a Shiny Marill! You'll also be able to complete event-exclusive Field Research tasks that lead to encounters with Marill.
For those who haven't played Limited Research Days before, they generally offer extremely high Shiny odds. With the exception of Community Days and Raid Days, these have historically seen the biggest boost to Shiny rates in the game. This is temporary of course, so the special green variant of Marill will only be easier to get during these hours.
Funny enough, Marill has seen a similar day in the past with an event structured very similarly to Limited Research Days. Back in mid-2020, we had GO Battle Day: Marill, which rewarded Marill encounters for PVP battles won rather than tasks completed. If you missed Marill during that day, this will certainly be an easier chance to earn your encounters. We can generally expect somewhere between ten to twenty pages of Timed Research during these events, with almost every single task rewarding an encounter, so by the end, your chances of not only a Shiny Marill but also a 100% IV Marill are quite high, as all of these encounters will have the IV floor that comes with earned encounters.
Best of luck to all those playin Pokémon GO for this event, and a Happy Mother's Day.