Clefairy and the Moon Stone

Brock joins Ash and Misty as they travel through the mysterious Mt. Moon. Our heroes soon encounter a Pokemon researcher named Seymour, who is studying the Clefairy. The Clefairy, as it turns out, worship the Moon Stone that lies in the heart of Mt. Moon. Team Rocket, as usual, tries to steal the Moon Stone and the Clefairy, but the Clefairy use their Metronome attack to drive the villains away.