Pokémon - Season 16 Episode 33 Butterfree and Me! Gotta catch 'em all!
Overview: On Wayfarer Island, Ash and his friends see the native Metapod and Butterfree, and when they find a Caterpie who has not yet evolved, Ash takes it upon himself to help the very lazy Pokémon join the rest of its friends, remembering the times he had raising his own Butterfree years ago.