Pokémon

While en route to Olivine City (Are we there yet?) Ash and co. stop at Whitestone. They notice three smeargle paining the town red, yellow and blue. Just as an angry mob was about to stop the Smeargle, their trainer appears and gives them a blank check and tells them to write any amount that'll cover the damages. Who is this man? And why does he think Smeargle art is so interesting?