>>27707433"When Raichu was first brought to Alola by vacationers, people were charmed by their attempts at mimicking surfers by using their tails to ride the waves and they were soon welcomed as favorite surfing partners of the locals.
It quickly became adept at sensing when the best waves would roll in, which, over time, led to Raichu developing strong psychic powers."
It's the best I can come up with and my new headcannon.
