Having arrived on Migration Island, Ash and company encounter a bunch of Metapod who evolve into Butterfree and then fly off as a part of the island's tradition. They find a Caterpie who didn't evolve into Metapod yet. Reminding him about his old friend, Ash decides to help Caterpie train, so it can evolve and leave with its family on time. With several obstacles like Ursaring and Team Rocket, will Ash help Caterpie evolve?
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