It is described in different ways in different Pokemon games and are as follows:
Red/Blue: When several of these POKéMON gather, their electricity could build and cause lightning storms.
Yellow: It keeps its tail raised to monitor its surroundings. If you yank its tail, it will try to bite you.
Gold: This intelligent POKéMON roasts hard BERRIES with electricity to make them tender enough to eat.
Silver: It raises its tail to check its surroundings. The tail is sometimes struck by lightning in this pose.
Crystal: When it is angered, it immediately discharges the energy stored in the pouches in its cheeks.
Ruby: Whenever PIKACHU comes across something new, it blasts it with a jolt of electricity. If you come across a blackened berry, it's evidence that this POKéMON mistook the intensity of its charge.
Sapphire: This POKéMON has electricity-storing pouches on its cheeks. These appear to become electrically charged during the night while PIKACHU sleeps. It occasionally discharges electricity when it is dozy after waking up.
Emerald : It stores electricity in the electric sacs on its cheeks. When it releases pent-up energy in a burst, the electric power is equal to a lightning bolt.
That Pokemon named Pikachu is soooo cute. =3
Chu = Mouse
1. Pikachu is an electric mouse found in the games, tv show, and movies of Pokemon.
2. The very reason why the show Pokemon shouldn't be aired anymore, in english... edited... Because the show has been KIDDYORIZED to attract small children, instead of the intended audiences of Early teens.
Oh yes Pikachu, harder!
That damn Pikachu shocked the hell out of me!
2. A cute, small pokémon that was crossed between a lightning bolt and a mouse. If you grab one's tail, it'll shock the pants off ya.
3. See pokemon, pokémon, pocket monsters, or electrical mouse.
Ash: Over here!
Brock: *Sees something* Oh! There you are! *grabs Pikachu's tail by mistake*
Pikachu: KACHUUU!! ->.<-
Brock: Eeeyaaaaaaah!!*dead* X(
"Pikachu says that he hates the director of pokemon and would like to take a shotgun to his head."