I was going to play a character inspired by Looney Toons in a game...

[Vulpis]

Hmm, seeing this, I wonder if you ever tried doing Doug under GURPS, Bob...particularly 4th Ed rules. For some reason doing him as having an Modular Ability (gah, I keep wanting to say a Variable Power Pool or Multi-Power, but that's Champions..I know GURPS 4th has something similar, but I'd have to look it up to find out what the exact name is), a free pool of points to buy powers from, with a set of limitations on activating/changing those powers. Or come to think of it, have you tried building Doug in Champions?