From PokéLand, the ultimate source for Pokémon info.

Pikachu
Pronounced	PEEK-uh-choo
Ability	Static
Type
Species	Mouse Pokémon
Size	Height: 1'04'' Weight: 13.2 lbs.
Evolution Line	Pichu → Pikachu → Raichu
Possible Moves	Thunder-Shock, Growl, Tail Whip, Thunder Wave, Quick Attack, Double Team, Slam, Thunder-Bolt, Feint, Agility, Discharge, Light Screen, Thunder

"Pikka Pika!"
-Pikachu, Pokémon Diamond & Pearl

Pikachu is an Electric-type Pokémon that appears in all four Pokémon Regions. It is the well-known as the mascot of the Pokémon series because of its appearance in the anime series.

Physical Appearance

Pikachu is short and chubby, and somewhat mouse-like in appearance. It has short limbs, long pointed ears and a lightning bolt-shaped tail. It has cute red cheeks (in which it stores electricity), black tips on its ears, brown colouration at the base of its tail and horizontal brown stripes across its back. Pikachu's alternate colouration (although this is very rare) is a dark orange.

Male and female Pikachu can be distinguished from each other by the shape of their tails. Male Pikachu have a staight-ended tail, whereas females have a dent in the end of theirs.

Game Locations

Pikachu is a forest-dwelling Pokémon. It first appeared in Pokémon Red and Blue, where is was rare. It could be found in Viridian Forest and the Power Plant. In Yellow, it was the only starter Pokémon avaliable, obtainable from Professor Oak in Pallet Town when the playet began his/her adventure. In Gold, Silver and Crystal, it again was quite rare and coulod only be found on Route 2. In Ruby, Sapphire and Emerald, Pikachu are rare, but can be found in the Hoenn Safari Zone and in FireRed and LeafGreen, they could be found in the same places as Red and Blue: Viridian Forest and the Power Plant. In Diamond, Pearl and Platinum, they are more common and can be found in the Trophy Garden on Route 212.

In Gold, Silver and Crystal, wild Pikachu han an 8% chance of holding a Berry. If traded from Red or Blue, a Pikachu would again hold a Berry, and if traded from Yellow, it would hold a Light Ball. In Emerald, Ruby, Sapphire, Diamond, Pearl and Platinum, there is a 50% chance of finding a wild Pikachu holding an Oran Berry, and a five per cent of one holding a Light Ball.

Evolution and Breeding

Pikachu is part of a three-stage evolution. A Pichu will evolve into a Pikachu via happiness, and a Pikachu will evolve into a Raichu when its Trainer uses a Thunderstone on it. If Pikachu or Raichu are bred, a Pichu will hatch from the egg. Pikachu belong to two Egg Groups: Ground and Fairy