Tottori Festival

 Tottori Festival was a Japan-exclusive event that took place in the middle of December, 2018. Shiny Sandshrew was released in this event.

Features
The event offered increased numbers of Sandshrew and Alolan Sandshrew in Tottori prefecture region.

Moreover, these Shiny Pokémon were released worldwide with the start of the event.

Announcement
The approximate translation for the event announcement was:

"To commemorate the “Tottori Festival” event, it will be easier to encounter Sandshrew and Alolan Sandshrew in Tottori Prefecture from Thursday, December 6 to Wednesday, December 19. Also, if you are lucky, you may be able to meet Shiny Sandshrew!"