Although they aren't black, the only cat I know that size is the Chausie. They are a hybrid of domestic cats and the wild jungle cat of Asia. Do a google images search on "Chausie" to get an idea of thier size. For example:
Part of me thinks it would be really neat to have a cat this large... and then sanity returns and I sit down with Gracy (our long hair) and I relax, thinking of all the things she isn't knocking over.