You can't, you have to breed Pikachu.
You can't catch pichu in Pokemon emerald,But you can get a male pikachu and a female pikachu or a ditto and breed them, When the egg hatches it will be a pichu
Put 2 pikachu in the day care
#155 in Hoenn is Pichu.
You can't catch Pichu because you have to breed him at the Old Man or Old Lady.
you cant catch a man in Pokemon ruby
I don't think you can actually catch a pichu but you can catch a pikachu at Viridian Forest and breed it with a ditto.
That is a fairy tale
no you can catch a charizard in pokemon ruby you can get it as a kanto starter
you can't catch seviper on Pokemon ruby (Pokemon sapphire only)
I'm sorry, but you can't catch Pichu in Pokémon Black / White. To get Pichu on Pokémon Black / White, you need to use Poké Transfer.
you have to breed pikachu or raichu
It evolves by happiness