You cannot catch Pichu or any of its evolutions in Pokémon Black, the only ways to get them would be via trading or through transferring with a previous game.
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 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
You can't catch Pichu because you have to breed him at the Old Man or Old Lady.
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
You can't, you have to breed Pikachu.
you have to catch them in the forest of picachu
breed pikachu/raichu
in pokemon pearl/diamond it is in the trophy garden
In the dream yard
to get complited pokedex and hatch pichu becose then you can catch north eached pichu.
First of all you CAN'T catch the Pikachu-Colored Pichu. You will have to get the event for it and transfer it over when they release it in your country.