Well,for the leopard I would have added more details. The lines look straight, maybe fluff thru up a bit with some fur. For the paws, you could try something like this.
https://s15.postimg.cc/petz174uz/beach.png
Or
https://s15.postimg.cc/5wzblbsij/1532979343133.png
(Lineart by Kekeywolf. Devianart. com)
Then you could go in and give the leopard cartoon like eyes, sorta like the wolf above. Black dots make it look extremely basic and simple.
For the horse:
Well, first, try a lighter background. The animal is extremely hard to see,even with full brightness.
Try fixing the ear. Keep horse atomony in memory. Swoop the ear forward a bit. And the chin needs fixed a bit. Here..just look at this:
https://s15.postimg.cc/q6wn0glxn/1532979820954.png
I would possibly work on mane a bit too.
There is a strip of white by the chin that you should finish coloring in.
However, despite this all,I love your work! I can see great things coming from you in the future ^^
Winter Month: 1 
Night 
Clear Moon: 
