Pokémon - Season 2 Episode 29 The Wacky Watcher! Gotta catch 'em all!
Overview: On Rind Island, Tracey meets Dr. Quackenpoker, a noted Pokémon Watcher who is doing a study on the Magikarp that climb up waterfalls and how they evolve into Gyarados. However, Team Rocket appears to steal the Magikarp and get them to evolve.