Pokemon Season 9 - Episode 420 – A Chip Off the Old Brock

During a training battle against Ash's Grovyle, Brock's Mudkip evolves into a Marshtomp. Marshtomp, with its newly gained power, injures a nearby Flaaffy. Now Ash and friends must go with Flaaffy's trainer to her grandmother's pharmacy to heal the injured Flaaffy.