Aliasing black_leopard → black_panther
Link to alias

Reason:

Or maybe it's better to just clean this out into melanistic and leopard if a black_panther should only be solid black. It looks like black_leopard is tagged when you can still see darker spots on the black fur.

They are both melanistic and essentially synonyms (I say essentially because "leopard" tends to be colloquially used for species of big cats that have spots, like you have mentioned).

That being said, based on what I see in black_panther spots it looks like they are being used interchangably regardless of their technical meanings, so I went ahead and approved this.