I say the Chimby, Drindian, and Roditore need ups in the art.
As Rei said (Sweeney), the Roditore needs a full update. I love how cute it is and all, but I can't stand to hatch until there are smother lines and etc. And if it gets colors.
Goiba WOULD be win if it had colors. But I don't mind the naturals that much =33