What official category is used for Pikachu in the Pokémon games?

Pikachu’s official category in the Pokémon games is Mouse Pokémon. This category appears in Pokédex descriptions and identifies Pikachu as a small electric rodent-like creature.

Pikachu is an Electric-type Pokémon first introduced in Generation I. Its Pokédex number is 025, and it evolves from Pichu when friendship is high and into Raichu when exposed to a Thunder Stone. Pikachu’s yellow body, pointed ears, red cheek pouches, and lightning-bolt tail made it the most recognizable visual symbol of the franchise.

The category is separate from Pikachu’s type. Electric is Pikachu’s elemental type, while Mouse Pokémon is its species category. This distinction causes common mix-ups, especially because the series often describes Pikachu informally as an electric mouse. Pikachu became the companion of Ash in the anime, although the game protagonist can obtain Pikachu in several different ways depending on the title.