Pokemon Go developer Niantic recently gave players another chance to catch Moltres as a reward for completing the game’s Global Challenge, but that isn’t the only special encounter fans have unlocked in the game. Niantic has also announced the Ultra Bonus Event, which kicks off this week and will bring four Legendary Pokemon from the Kanto region to Raid Battles for a limited time.

First, beginning September 13, the three Legendary birds Articuno, Zapdos, and Moltres will return to Raid Battles around the world until September 20. Not only does this give you another chance to catch any of the three you may have missed, you’ll also have a chance to encounter their Shiny versions during the event. Additionally, other Pokemon originally from the Kanto region will appear much more frequently in the wild and in Raid Battles until September 30.

Most exciting of all, the Legendary Psychic-type Mewtwo will begin showing up in Raid Battles just as the three Legendary birds leave on September 20. Mewtwo was previously only available as part of the invite-only EX Raids, making this the first chance all players will have a chance to capture the powerful Pokemon. It’ll remain in Raid Battles until October 23.

Finally, Niantic is offering another way to get your hands on the rare, region-exclusive Kanto Pokemon Farfetch’d, Kangaskhan, Mr. Mime, and Tauros. Through the end of September, you’ll be able to hatch the aforementioned monsters from 7 km Eggs. You can read more details about the Ultra Bonus Event on the official Pokemon Go website.

September 20 also marks the day the Hoenn Legendary Pokemon, Regirock, is slated to leave Raid Battles, making this your last opportunity to add one to your collection if you haven’t already. Shortly after it leaves, Niantic will host September’s Community Day event, which takes place on Saturday, September 22 and features Chikorita, the Grass-type starter Pokemon from the Gold and Silver versions.

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