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
in pokemon pearl/diamond it is in the trophy garden
breed pikachu/raichu
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.