I did this prior to the visit to SDCC 'o6 in the middle of this year. It started out as a sketch - real crappy with skewed eyes and whatnots hahaha. Scanned and cleaned up digitally (sorry, I can't find the cleaned up lineart, and at this point can't be arsed to find it >.<) and finally coloured and abused with much Photoshop brushes. See the dinky sketch here.
And don't laugh!