First partner Pokémon
From Bulbapedia, the community-driven Pokémon encyclopedia.
Starter Pokémon are one of the Pokémon that a player can begin a game with. Each one starts out at Level 5 with two basic moves: one attack and one attack to lower the opponent's stats. These moves are generally weak moves. The three starters are of three specific types: Fire, Water, and Grass. The one exception so far has been Pokémon Yellow, where the player starts out with Pikachu the Electric type. Your rival always picks the starter that has a strenght against the player's starter.
Starters:
Red, Blue, Green, FireRed, LeafGreen: Bulbasaur Charmander Squirtle
Yellow: Pikachu. The rival starts with an Eevee that will become a Flareon, Jolteon, or Vaporeon depending on the outcome of battles.