The legendary Pokemon of Gen 3 — Groudon, Kyogre and Rayquaza — are returning to Pokemon GO simultaneously for a limited time. According to Niantic, this special event is in honor of the “year of legendary Pokémon,” and it will feature all 3 legendaries appearing in Raid Battles all over the world.

Starting today, Feb. 23, and going until March 5, the Pokemon will appear in various Gyms. To further incentivize the event’s participation, Niantic has stated that if more Rayquaza are defeated than Groudon and Kyogre combined, it will be easier to hatch Pokémon commonly found in windier weather. While if more Groudon or Kyogre are defeated than the other 2 combined, they will make it easier for sunshine- and rain-loving Pokémon to hatch, respectively.

Interesting rewards for an interesting objective. At least there’s more to the grind than simple stardust collection. The event has already begun, so you can begin as soon as now.

Have fun, trainers!