Megantereon whitei was a smallish but heavily-built sabertoothed cat from the late Miocene of Africa, related to Smilodon. A bone flange on the chin protected the saber fangs, which gives it a very Bruce Campbell look. I've painted this one a bit on the skinny side, as you might expect from a nursing mother. The coat pattern is based on a tiger with the abundism mutation.
You can see the line art and a WIP here: http://viergacht.tumblr.com/post/87636542857/wip-sketch-and-starting-to-paint-megantereon