"This is a black female Jaguar that I captured at the amazing WHF in Kent. The Jaguar is the largest feline on the American continent, and is the only one of the world's 'big' cats to be found in the New World." AKA a panther.
Black panther carrying her cub great shot here to see the pattern on the mother's coat. Panthers aren't a breed they are a coat color that occurs among Leopards and Jaguars. They are black with black spots. This looks to be a Jaguar.