A black panther is typically a melanistic color variant of any Panthera species. Black panthers in Asia and Africa are leopards (Panthera pardus). Black panthers in the Americas are black jaguars (Panthera onca).
"Course he isn't safe. But he's good. He's the King, I tell you. Beaver, answering one of the Pevensie children's question about whether or not the lion Aslan was safe (Aslan represents God in the allegorical series The Chronicles of Narnia)