Rating: 8 Nice job! I really like the green shoulderpads and the back-cloth. On the other hand I would work more on the fur: more contrast and some tone variations would make it stand out much more.
Rating: 8 Great use of colour and tone. Only nit-pick would be the eyes... You have given him human-like eyes but rats generally have dark brown or black eyes (or pink for albino domestic rats) with no white in them showing at all.