You can transfer from HG/SS to B/W if you obtained them their, or transfer from a Ruby/Sapphire/Emerald to a Gen IV game then to B/W. But otherwise it is currently only available as an event Pokemon in Japan.
How to change your username How to add a user avatar Why was my post hidden? Question etiquette Flags vs Downvotes Anime FAQ Official PokemonDb League
Type a Pokemon name, type, move or ability to see instant results.