Bergmite, the ice chunk Pokémon from Kalos, can be found in the wild in Pokémon Go. Yes, Bergmitecan be shiny in Pokémon Go!
Avalugg and Hisuian Avalagg actually aren’t horrific when it comes to PvE meta, as they can be used as ice-type attackers. They’re also pretty bulky, making them great for plunking down in gyms and holding their weight against incoming attacks.
Note that you cannot evolve Bergmite into Hisuian Avalugg. Despite being part of the same family, you can only get Hisuian Avalugg from raids.
What is the shiny rate for Bergmite in Pokémon Go?
As per old research by the now-defunct website The Silph Road (via Wayback Machine), the shiny rate for Pokémon on a regular day is approximately one in 500. Bergmite is not a confirmed Pokémon that gets a “permaboost” (meaning that it’s a rare spawn and thus gets a boosted shiny rate).
What can I do to attract more shiny Pokémon?
Not much, unfortunately. It appears to be random chance. Shiny Pokémon catch rates are set by developer Niantic, and they are typically only boosted during special events like Community Days or Safari Zones, or in Legendary Raids. There are no consumable items that boost shiny Pokémon rates.