okay so I don't do critiques often and this might suck so sorry in advance xD

I'm gonna go through this addressing it piece by piece if that's alright!

The character:
This character is fairly unique but I think you got the anatomy down pretty well! The first thing I noticed is that there's a lack of shading on the front shoulder here, and not much variation in color overall. Light from the sun and light bouncing off of the snow even would have a color effect on the character- my suggestion would be to add lighting to areas which would catch it the most, and color the light accordingly (yellow/white light from above, blue-ish light from below). Areas that would get a lot of light would be the shoulders, cheeks, and mane/tail. I think you have a good start on the shading- I really like the way the shading on the tail shows the curve of it- but you need to enhance it to really show the anatomy. Go even darker and don't be afraid to move around the color wheel to get more variation in color! A good rule to follow is to balance warm and cool colors- so if you use warm colors to shade, you should use cool colors to lighten, and it makes a nice balance! It can also be applied the opposite way, of course. I also think it would be a great idea to focus on the tail/mane for shading. Try out different fur tutorials and find stuff you like! It's hard at first but you'll adjust your own style and be able to paint fur detail nicely. The last think I wanna say about the character is in the face- the anatomy looks fine to me, but I would suggest a darker brush to paint around the eyes and even the nose and mouth a bit to enhance them!

The background:
The background looks pretty good to me! I'm not great at painting them and I think you're going strong with them. But there's stuff I see that can be adjusted. (First let me just compliment your painting of the snow, I think it looks really great, especially the curved area in the lower right!!) I think the biggest thing you should focus on is defining more detail in the trees. You don't necessarily need to worry about painting bark (I don't hah) but more shading would never hurt! And again, playing with colors is a great way to go, especially since trees often have varying colors of brown, green, and gray. Also, a backgrounds rule in general is to make your foreground more saturated than your background. The trees further back should be less saturated with color, which gives the effect of distance. I like that you blurred the trees in front of the character to show that they are close to the 'camera', though! But, I think the placement of them takes away from the scene a bit- I would suggest a smaller/thinner tree if you are going to put it in front of the character. Also, the small bit of tree on the right- which I assume is a stump, but I'm not sure if that's what you were going for, sorry D: - could have more stump detail. For example, a stump would have the paler inside showing, and the top would be jagged and ripped looking if the tree fell of natural causes. It's up to you!

Overall:
A big thing I noticed is there isn't a defined light source. Make sure you define one! Even if it's nighttime, there will always be light from somewhere- moon, stars, whatever. Figuring out your light source is great because it helps you when shading and highlighting. Another thing I'll mention is the direction of the character- it appears to be walking forwards, but the tail is swept all the way around in the same direction. This isn't impossible, but it may make more sense to place the tail in a position in which momentum would be pulling it. Maybe trailing behind the character, or swept up in the tail a bit if it was moving it's tail?

I hope this didn't seem harsh at all!! It isn't meant to be! If anything doesn't make sense just let me know and I can explain it best I can! c: Also, if you want links for help, I know plenty of tutorials for fur/shading/backgrounds that you might like! I would definitely suggest reviewing tutorials- even if you don't actively practice each one, the methods will be planted in your mind. Also, try browsing paintings by other artists, I find that to always be both inspiring and helpful!

Keep up with your good work<3 Your painting skills aren't bad at all!! I think with a bit of practice you can make some really great stuff! <3 good luck!