Black panthers are any member of the big cat family (roaring and non-roaring) that are born with an entirely black or very dark pelt. So a black panther isn’t a certain species of cat, but a color.
For example, a black panther in South America or Asia would be a black jaguar. In Africa and India, it would be a black leopard. If there were black cougars or tigers or lions or cheetahs (and some of these have been reported), those could also be called black panthers.
Let’s look at the most common black panthers, jaguars and leopards, below. Beautiful!