The first of the many.
A special distribution has started for Pokemon Sun and Moon as part of the celebration for the upcoming Pokemon: I Choose You! movie. By entering the code PIKACHU20, players can get a special Pikachu wearing Ash’s original hat from the animated series. The special Pikachu will be LV1, and holds a special Z-Crystal Pikashunium Z.
However, please note that each player can only get one Pikachu, and Nintendo is set to release more hat-wearing Pikachus in the future, so think twice before deciding which Pikachu to get.
Personally, I’m getting this Pikachu and the one wearing Ash’s hat from Kalos. I have both Pokemon Sun and Moon.