Pikachu is the player's starting partner in Pokémon Yellow.
Pokémon Yellow is an enhanced version of the first-generation games, released in Japan in 1998 and internationally from 1999 to 2000. Its story and setting remain based on Pokémon Red and Blue, but the game was designed to resemble the television anime more closely.
Professor Oak gives the player Pikachu at the beginning, and the Pokémon follows the player outside its Poké Ball. Pikachu also refuses to evolve with a Thunder Stone in the game, reflecting the anime's decision to keep Ash's partner in its original form. The rival begins with an Eevee, creating a different opening matchup from the original games.
The player can still obtain Bulbasaur, Charmander, and Squirtle during the adventure. This makes Yellow distinct from Red and Blue: the first games let the player choose one of those three Pokémon immediately, whereas Yellow guarantees Pikachu as the opening partner.