The cat in the pic would be a melanistic leopard. The only possibility for a black cat of that size would be a melanistic jaguar, and we are quite a ways off from their northernmost range. You can tell it's a leopard from the head/neck structure and the tail. Jaguars are much thicker and heavier than leopards, particularly at the head/shoulder area. Their tail is also very thick. There is also no such thing as a "black panther" in America, no matter what anyone's uncle's best friend's papaw saw. Unless of course you're speaking of a certain social faction of anti-white racists. Cool pic though!