If you live in North America, you’ve probably heard a story about someone seeing an elusive “black panther” somewhere. And by black panther, I don’t mean the superhero movie that just came out or the black militants who carried guns and wore berets back in the 1960s.

No, I’m talking about a big cat with a black coat.

There have been sightings of these creatures in pretty much every state and even Canada. In fact, “black panthers” have also been sighted in England and Australia. But what exactly are they, and do they exist?

Well, the term “panther” is really just a generic term for any big, wild cat. It comes from the genus name Panthera, which includes lions, tigers, and jaguars. Of those species, jaguars are the only ones that are sometimes black, or melanistic, although even melanistic jaguars have spots that are visible up close. Cougars or Mountain Lions (genus Puma)—which are the only species of wild big cats in North America north of the Rio Grande—are not of the Panthera genus, nor do they have a gene for melanism.

So, what are the black panthers all of these people are seeing?

Since the nineteenth century, there have been numerous reports of “black panther” sightings across the United States. “Panther” generally refers to a big cat, while most experts believe the black color seen by the witnesses is almost always a mistake.

Many experts believe that some of the black panthers sighted are actually melanistic ocelots—a small wildcat native to Mexico that occasionally wanders into the American southwest. That might explain some of the sightings, but it can’t explain all of them, especially when there has been video documentation in some cases.

Some people who have claimed to have seen black panthers believe they are melanistic jaguars that have made it north of the Rio Grande, while others think they are a previously undiscovered subspecies of cougar. If these are an undiscovered species, this would make them a “cryptid.” But skeptics are not so sure.

Skeptics believe that in the vast majority of cases the witnesses have in fact seen a cougar, but due to lighting and distance the animal appeared black. In the few cases where there is photographic evidence, skeptics point out that the size is often undetermined and the context of the film is questionable, so a proper judgement can’t be made.

I guess that means that the elusive black panther will remain a legend until one is caught.