We went through this several years ago when a local highway patrol officer filmed a black cat behind his house. I saw stills of the video and it looked like a black panther to me. He got the local game warden involved as well as a biologist or two that all said the melanistic gene doesn't exist in a mountain lion. They finally discovered the black cat was a huge (for a cat) feral cat. Not nearly as big as a lion but the way it looked on film it looked far away and huge.
Optical illusion, wishful thinking and an imagination.
And no, I don't believe in Bigfoot either.
