Pokemon Go developer Niantic is holding an Extraordinary Raid Week event in the mobile game. The event starts Tuesday, May 21 and runs through May 28 at 1 PM PT/ 4 PM ET/ 9 PM BST. Throughout the week, new Pokemon Bronzor will appear in Tier 1 Raids, as will its Shiny form. You can also potentially find the rare Clampearl as one of the Tier 2 Raid bosses. On top of that, you'll receive twice the usual amount of Stardust and XP for participating in Raids.