Pikachu is the mascot and companion of the player in Pokémon Yellow.
Released in Japan on September 12, 1998, Pokémon Yellow is an enhanced version of the first-generation Game Boy games. It was designed to resemble the Pokémon anime more closely, so Pikachu becomes the player’s partner rather than one of the three selectable starters.
Pikachu follows the player on the overworld and refuses to evolve with a Thunder Stone while it remains the player’s partner. The game also gives players opportunities to obtain Bulbasaur, Charmander, and Squirtle, echoing Ash’s anime journey and the original game’s starter choices.
Pikachu’s role in Yellow helped establish the character as Pokémon’s worldwide mascot. The game was later released internationally in 1999 and 2000. It should not be confused with Pokémon Let’s Go, Pikachu!, a much later Nintendo Switch remake inspired by Yellow.