Update: Pokemon GO‘s developer, Niantic, made an official statement to IGN regarding the appearance of the legendary birds.
“We recently noticed that a few Legendary Pokemon got into a few accounts when they shouldn’t have, To preserve the game’s integrity and as a measure of fairness, we have rectified the situation and revoked the legendary Pokemon from the Trainers’ accounts.”
Original: The first legendary bird may have made its appearance in Pokemon GO.
The first citing comes from a Pokemon Gym in Ohio, where an Articuno is currently taking over on Team Mystic. The user claims to have been rewarded with this Articuno after emailing Niantic about issues with Pokemon GO. As a reward, Niantic gave out this very rare legendary bird, however, there was no proof of the email posted and Niantic has yet to make an official statement regarding the existence of the legendary birds in the game.
Since the initial discovery, a team member from Team Instinct claims to have discovered an Articuno in the game. This leaves dust to the rumor that Articuno would only be available for those on Team Mystic, as the team shares the bird’s shape as it’s logo.
Pokemon GO is available for iOS and Android devices.