One of my all-time favoriete RPG books has been Transdimensional TMNT -- to be frank, not so much as a rulebook (though it's quite good), but as the gateway to getting into the Cerebus comic and fostering my enjoyment for many things indie-media related.
(As Pundit is probably off chasing his eyeballs that more than likely popped out of his sockets and rolled out the door in protest after reading that, I'll use the opportunity to explain that Trans-TMNT makes several references to a TMNT issue where the Turtles travel back in time to meet Cerebus and hi-jinks ensue.)
To make a long story longer -- not that I'm particularly fond of statting iconics as they're generally poor attempts (Amber being a notable and exceptional exception) but was statting Cerebus the Aardvark ever discussed?