Pikachu is an Electric-type Pokémon introduced in Generation I. It is also known as the 'Mouse Pokemon'.
How to Obtain
Pikachu can be obtained in the grass patch at the top of Route 1 where the NPC is standing in the grass. It can also be obtained by evolving Pichu, found in Mysterious Grotto, with a Friendship Ribbon, trading, or Pokémon Roulette.