While not all of the Pokémon that have gotten Spotlight Hours in October have shiny variants available, Shuppet’s shiny version is available in the game.

Originally introduced in Gen III, Shuppet and its evolution, Banette, are both available in shiny form in Pokémon GO, though your best bet to get the later evolution is to evolve it from Shuppet.

Source: https://www.distractify.com/p/can-shuppet-be-shiny-pokemon-go