The design is very graphic (like an old UPA cartoon such as Mr. Magoo), which in my opinion is great considering how bland a lot of CG Animation still looks despite advances in rigging and animation technology. My biggest critique is simply that you should have increased the Render Samples (I'm assuming you're either using Cycles in Blender or Arnold in Maya)--the shadows have some rather ugly and noticeable noise. I know it takes forever to render, but especially for a single image like this here, one should be willing to wait as long as necessary to get a clean, crisp image. Also, when you are done rendering, maybe you can bump up the saturation of the colors in a photo editor like Photoshop or Gimp? The slightly desaturated tones imply that this is a depressing scene set in a factory farm or something, which I don't think you're going for. Making the backdrop any color other than gray would also help a ton. Finally, maybe try to learn how to make textures and bump maps, especially for the clothes, to create the illusion of more detail?
Again, though, the actual character design and 3d model is actually fantastic for a beginner, my critiques just have to do with literally every other aspect of the CG character pipeline, like lighting, color and texturing.