As requested, the Snow shader for Blender that I used in several of my wildlife art is finally available.
Made for Blender 2.8+ Cycles, it comes with a .blend scene file featuring a simple snowy terrain. You can use the material in all your Blender scenes by simply appending this .blend file and selecting the SnowShader material asset, which you can later apply to whatever object you want.
I also suggest adding a "Subdivision Surface" modifier to your objects in order to take full advantage of Blender's micro-displacement capabilities, which deliver an excellent level of extra-detail.
The Snow shader can be customized to best fulfill your needs: you can change displacement scale, mapping scale (to adapt the shader to objects of different sizes) and of course you can fiddle with color, specularity, randomize settings of noise nodes in order to get infinite variations.
Note: animal 3D models not included.