Well to start, I think trying the foreshortening in the bottom character's leg is a great idea. That kind of composition really makes a picture feel really dynamic. I also like the highlight effects that you have on the arm and tail. I will say that the choice of a pure black background really makes it hard to see the bottom character's legs at all. I, at first, didn't really know what I was looking at. I would say a very dark grey for the pants or some more obvious highlights would help this, or changing the background color to a dark color of some kind. Keep practicing and looking at source photos of your subjects and you'll grow all the time. Great job!