Shiny Tapu Koko distribution for Europe and Australia (Update: North America too!)

It’s available right now through Mystery Gift! Get it for your copies of Pokémon Sun and Moon.

List of American region serial code event Pokémon distributions (Sun, Moon, Ultra Sun, and Ultra Moon) - Bulbapedia, the community-driven Pokémon encyclopedia

English - Project Pokemon Forums

Distribution] Shiny Tapu Koko Mystery Gift is Available now in PAL Territories - Miketendo64

Shiny Tapu Koko Event now live in NA, Europe, and Australia! - Ending August 14th! - General Pokémon Forum - Neoseeker Forums

SM - North America Shiny Tapu Koko - Event Pokémon News - Project Pokemon Forums

Get a shiny Tapu Koko from mystery gift!

English - Project Pokemon Forums

Shiny Tapu Koko RELEASED! How to Get Shiny Tapu Koko in Pokemon Sun and Moon

Marowak

Tapu Koko, Pokémon GO Wiki