Pikachu became the main mascot of the Pokémon franchise.
Pikachu is an Electric-type Pokémon introduced in the first-generation games. Its bright yellow design, red cheek markings, pointed ears, and lightning-bolt-shaped tail helped make it especially recognizable among the original 151 species.
The television anime strengthened Pikachu’s worldwide identity by making it Ash Ketchum’s partner. In the first episode, Professor Oak gives Ash Pikachu after the other starter Pokémon have already been chosen. Pikachu initially resists Ash’s commands, but their relationship develops into the central partnership of the series.
Pikachu is not the first National Pokédex entry—that is Bulbasaur—and it is not the strongest Pokémon by any universal ranking. Its mascot status comes from visibility and cultural importance across games, animation, merchandise, trading cards, and promotional events. The character also appears in the title of Pokémon Yellow, an enhanced Game Boy version inspired partly by the anime.