Well I think the BG could do with being made black or a darker red, and the overall AA inmproved, as well as AAing the white outline.
Also, muck around with values on the greys and white to add some subtle colour to them. Furthermore, I think the shading on the neck, and the form of the ears could use some revision.
Overall pretty cool design, but your understanding of AA seems a bit limited... (This isn't meant to be an insult.)