Pikachu:
Pokemon's Pikachu has electricity storing pouches on its cheeks which are supposed to get charged when Pikachu sleeps. Pikachu is yellow in color with black tipped ears and a lightning shaped tail. Pikachu is evolved from Pichu. Although it lacks a typical natural evolution, Pikachu evolves into Raichu through a Thunderstone. Pikachu discharges electricity, and if it does not, it leads to a flu type illness.
Pokemon's Ash And Pikachu:
Pikachu is Ash's best friend in Pokemon. Initially, Pikachu did not like Ash, and it used to zap him with electricity when he came near. But later on, Ash put himself in danger and saved Pikachu, thus winning his lifelong friendship.