>>29430184>>29433271It's possible that Shiny Forms are actually rare forms of the Pokémon that evolved in different environments.
So purple Muk are most common in Kanto, and Green are most common in Alola.
But very rarely, you may find an "Alolan" aka Shiny Muk elsewhere, except without the Hawaiian crystallized garbage and oil spills.
And vice versa, in Alola, you may be lucky enough to find a "Kanto" Shiny Muk but with the local oil spills and crystallized garbage now a part of its body.