Vee (ブイ; Vui) is one of Red's main Pokémon.
Vee was originally a test subject of Team Rocket's, who experimented on it in order to give it the ability to transform freely between its three Generation I evolutionary forms.
Red encounters Vee while on a request from Erika to find an Eevee. Vee, unlike normal Eevees, is able to transform between Vaporeon, Jolteon, and Flareon, causing great confusion to Red during battle. After figuring out that Vee uses its ears to sense which typing an enemy Pokémon is, Red blocks its ears and defeats it. Eevee then begins to writhe in pain, causing a bewildered Red to rush angrily to Celadon Gym to question Erika's intentions. There, Bill and Red learn of Vee's past with Team Rocket. Red places Eevee on a healing device, but Erika attacks with the intention of killing the Pokémon. Despite Red's efforts, he is ultimately defeated by Erika, but a last minute rescue by Pika manages to keep Erika from committing the deed. Erika then apologizes, revealing that she had been testing Red the entire time. She gives Vee to Red, and the two head off.
Vee isn't seen again until Red's battle with Sabrina at Silph Company. Here, Sabrina throws the injured Vee at Red, revealing that they had stolen him from Professor Oak's Laboratory in order to continue their research into creating Thu-Fi-Zer.