Professor Oak (anime)/I Choose You!

Professor Oak appeared in I Choose You!, which is set in a timeline separate from the main series. He welcomed Ash when he showed up late at his laboratory and informed him that, , and had already been chosen by other Trainers. Nonetheless, he had a fourth Pokémon to give to Ash, a stubborn Pikachu. Ash chose Pikachu, and as such, Professor Oak gave him its Poké Ball. Pikachu immediately proved to be quite the problem for Ash, as he shocked him and Professor Oak.