The Eevee brothers are four Pokémon trainers from the Pokémon anime, three of which whose signature Pokémon are Eeveelutions. They make their appearance in The Battling Eevee Brothers.

Rainer, Sparky, and Pyro appear to be the same age, possibly triplets. Mikey is notably younger than the other three brothers.

The brothers

Rainer

Rainer has dark blue hair styled to look like fins. His signature Pokémon is Vaporeon. He boasts it is the best because it can melt into water and disappear by using Acid Armor. His English voice actress is Maddie Blaustein.

Sparky

Sparky has golden hair styled in tall spikes. His signature Pokémon is Jolteon. He boasts it is the best because when angered, its fur becomes sharp as needles which it can launch at the opponent using Pin Missile. His English voice actor is Matt Mitler.

Pyro

Pyro has red hair styled to look like flames. His signature Pokémon is Flareon. He boasts it is the best because of the powerful flames of Fire Spin. His English voice actor is Matt Mitler.

Mikey

Mikey has plain brown hair with bangs shaped to resemble an Eevee's fur collar. He trains an Eevee, and commands it to use a move called Rage Tackle. His English voice actress is Kayzie Rogers.

All of Mikey's brothers fight over how Mikey should evolve his Eevee. Despite the fact that all his brothers want to see him train an Eeveelution as well, he prefers keeping his Eevee just the way it is. He doesn't have the courage to tell his older brothers this, but after some advice from Misty, he decides to try anyway. His brothers eventually come to accept Mikey's choice, and it actually seems to bring them closer together as brothers.

In the Electric Tale of Pikachu manga

Mikey wanted to join the Knights of the Evolution Stone like his brothers did. Rainer, Pyro and Sparky told Mikey the only way for him to join the Knights of the E-Stone was to evolve Eevee. Mikey proved he didn't need to evolve his Eevee by defeating his brothers in a battle.

Trivia

• The Eevee brothers have no representation in their family of the Generation II Eeveelutions, Espeon and Umbreon, nor the Generation IV ones, Leafeon and Glaceon. There was originally fanon speculation that something might be done to correct this, but like many characters of the day, the Eevee brothers have made no reappearance on the Pokémon anime since their debut episode.
• This was not the only group of siblings training Eeveelutions to appear on the Pokémon anime. When Ash and his friends went to Johto, they met the Kimono Sisters who, like their counterparts in Pokémon Gold and Silver, each trained one of the five evolutions. Unlike the Eevee brothers, though, they had no representation in their family of Eevee itself.
• The name Sparky was used again in the anime as the name of Ritchie's Pikachu.