Vaporeon

Vaporeon is an Eevee that has been exposed to a Water Stone. It lives close to the water, and its long, ridged, finned tail is often mistaken for a mermaid's. In "The Battling Eevee Brothers" one of Michael's older brothers' favorite water Pokemon is a Vaporeon. He tells Michael that he should use a Water Stone to evolve Eevee into Vaporeon. But when Team Rocket arrives, Vaporeon is defeated quickly by Ekans and Koffing.

First appearance: Episode 40 — "The Battling Eevee Brothers"