Niantic has announced the first slate of Pokémon GO raid bosses for October, and they're exactly who many trainers predicted. Zapdos will leave raids on October 2nd, replaced by Moltres. The Fire/Flying-type Legendary bird will stay for a week, before being replaced by Giratina Origin Forme, which will be available Shiny for the first time in the game.
Zapdos had already been announced in the September blog post from Niantic, and it will reign over five-star raids in Pokémon GO from Friday, September 25th at 1 PM to Friday, October 2nd at 1 PM Pacific time. Its predecessor Articuno came with the surprise Legacy Charged Attack of Hurricane, so the expectation has been set that Zapdos will have the Legacy Fast Attack of Thunder Shock.
Moltres will replace Zapdos on October 2nd at 1 PM and will stay in raids until the following Friday, October 9th at 1 PM local time. If it follows the same pattern of Legacy moves, it is expected to have the Legacy Charged Move of Sky Attack.
Finally, Giratina Origin Forme will replace Moltres on October 9th at 1 PM and will stay in raids for two weeks, until Friday, October 23rd, which will give this Pokémon two raid hours on the two Wednesdays between its arrival and departure. Though this Pokémon was featured in GO Fest 2020 for one day, it has been over a year before it has had a full spot in a regular raid rotation. This is also the first time that this Origin Forme of Giratina will be available Shiny, making this top meta Ghost-type attacker one that Shiny hunters are going to want to raid hard.
After Moltres and Giratina Origin Forme leave raids, Niantic has a surprise just in time for the holiday event, which they're calling a "special Raid Boss."
Our two cents? We're thinking Mewtwo will arrive for a single week, before leaving the rotation again for a long, long time.