That thing in the comic book cover photo Marrakai posted doesn't even look like a cougar...the tail looks much too thick like a kangaroo as another poster mentioned....and those dinky front legs look a lot more like a roo's front legs...to me it looks like roo roadkill that had it's head run over by a truck and was later picked up and dyed black. The visible meat looks as dark as roo meat, which is darker than one would expect on a cat. Also according to a number of wildlife biologists, cougars (aka panthers or mountain lions) don't have the genetics to allow solid black. My understanding is that the only verified large black cats of North American origin never occurred farther north than South Texas.

Of the two cougars I've seen in my life (both in the USA), one was under the shade of a tree and I thought he was as black as black can be. He saw me and ran, once he was in the sunlight it was obvious that he was tan or golden in color instead.

Here is some more information, the Jaguarundi link is to the "black panther":
Mountain Lion
Jaguarundi

Richard