Been a while since I did a big cat design. In that vein, following up on the Amazon folks, here is the only American big cat: the mighty jaguar.
Ever wonder how you tell the difference between a jaguar and a leopard? Here's a handy chart explaining it, though, if you're seeing it in the wild, the first question you should ask is "Am I in the Americas?" If your answer is yes, then it's a jaguar. If not, it's a leopard.
The actual easiest way to tell is that a leopard has black-edged spots with a light center. Jaguars have larger black-edged spots with a darker center and little dots inside the big spot. Also, jaguars are thicker and stockier. Leopards are more lithe.
Best not to go check it out anywhere outside of a zoo, though, lest you find yourself unwitting prey.