Pokemon Go added Shiny variants of several Pokemon species to the game, but then removed them from the game. Chicago is hosting the third ever Pokemon Go Fest, a live event held by Niantic that gives players a chance to catch rare Pokemon and participate in special in-game events. As part of this weekend's festivities, Niantic announced that players around the world could now catch the Shiny version of Horsea in Pokemon Go. However, Pokemon Go Fest attendees who arrived to the event early on Thursday reported that Shiny versions of Abra and Clefairy were spawning instead of Shiny Horsea.
Unfortunately, the additions of Shiny Abra and Clefairy were apparently a mistake. Abra and Clefairy were quickly swapped out with Horsea, and players have not found another Shiny Abra or Clefairy in the wild since. Players attending Pokemon Go Fest have reported Niantic staff at the event stating that Shiny Abra and Clefairy were added in error. We'll note that players can still obtain Shiny Clefairy by hatching a Pokemon egg containing a Shiny Cleffa, which was added to the game back in February.
Shiny Pokemon have variant colorations than normal Pokemon and are prized for their rarity. Shiny Horsea has turquoise skin instead of its usual light blue, Shiny Clefairy has green-tipped ears, and Shiny Abra is slightly more pale than its normal forms.
Players hunting for Shiny Pokemon this weekend can still benefit from Pokemon Go Fest, even if Shiny Abra and Clefairy are no longer available in the wild. The Silph Road reports that Shiny Pokemon are appearing at a boosted rate around the world. While players at Pokemon Go Fest seem to have the best luck, players anywhere can still benefit from the boosted rates until Pokemon Go Fest wraps up this weekend.