While traveling through the Eevee forest, Crystal caught an Eevee and trained it until it evolved into Vaporeon. He was confirmed male when he tried to hump Eve, Gabe's Espeon in A Visit From An Old Friend. Crystal's Vaporeon is known for having a crush on Eve. When Crystal met up with Gabe, Team Rocket captured Vaporeon and the rest of Gabe and Crystal's Pokemon with a net. But the Pokemon were rescued by their trainers. When Team Rocket's Butch & Cassidy captured Crystal's Vulpix, Crystal sent out her Vaporeon who helped her get Vulpix back. Crystal often uses Vaporeon in battles. In The Poochyena Forest, Gabe's Pikachu, Pik, Char, Gabe's Charizard, Crystal's Vaporeon, Katrese's Delphox, Katrese's Mudkip, and Katrese's Poochyena were captured by Team Rocket to take to the boss. When Gabe sent out Eve, Vaporeon was happy to see her and was glad when she and Crystal's Bulbasaur rescued him and the rest of Gabe's Pokemon. As the Kalos season went on, Eve developed a crush on Crystal's Vaporeon and accepted his love. In Vaporeon & Eve Make Love, Team Rocket attempted to capture Crystal's Vaporeon and Eve to take to the boss for a big payment, but they were rescued by their trainers.
Vaporeon is sneaky sometimes, especially when he tries to hump Eve. He has a major crush on Eve and is determined to impress her. He is loyal to his trainer and accepts her love for him. He is a very caring and friendly Pokemon.