Pokemon Go fans are speculating about the details of the next big in-game event and update.

And it appears the next Pokemon Go event could involve Pikachu and some nifty new hats.

To celebrate the 20th anniversary of the anime series and the release of the 20th Pokemon movie in July, Pokemon Sun and Moon players have a chance to download one of six different Pikachu models, each wearing one of Ash's hats from the TV show.

Fans can get a code for the Pokemon Sun and Moon hats by pre-ordering tickets for the film.

Nothing has been announced for Pokemon Go, but an advert for the promotion suggests that the Niantic app could get something similar.