Well, duh, it got popular. No one really animates pantherines all that well, not even their roars. Imagine a similodon, or the saber tooth tiger (now considered lion since dna matches more lions than tigers). Very few people animate any feline very well, even fewer understand their minute movements as they react and adapt to changes in their environment while consecutively preparing for their next action.
When you animate this, whether its a feline saber or not (there were many saber species in prehistoric times) it's movements are natural. Not glitch, or full of fake twitches that you'd normally never see in the wild. Down to the bow of the head after the roar is completed, most roaring predators do that, as a natural action to catch breath.
So, in short. The animation is sketchy and unfinished, but excellent in in natural movements, speed and flow. I congratulate you .
PS: Not a good animator, but I'm a very strict critic... If I say I like something I mean it. And when it come to animals, my criticism can go on turbo mode.