What are Swarm Saturdays?
Swarm Saturdays is an event first introduced in June of 2017. The challenge is to capture as many swarming Scatterbug as you can before the end of the Saturday. The event lasts for the entirety of the first Saturday of each month.
During the event, swarming Scatterbug randomly appear on pages of the RPG. If you spot one, you can click the image. A page appears with a captcha code. After entering the correct code, the Scatterbug is logged as being caught by you. Rankings can be checked along with the number of Scatterbug logged under the Swarming Pokémon tab in Challenges.
The Scatterbug will look like this: 
Prizes are distributed based on the rankings at 12am on Sunday. If there is a tie for first place, there will be no grand prize.
The prizes are listed below:
|GoldenScatterbug + Shiny/Dark Scatterbug|
|ShinyScatterbug||February, April, June, August, October, December|
|DarkScatterbug||January, March, May, July, September, November|
- Currently bugged, wherein the event occurs on every Saturday, rather than just the first Saturday of the month.