Here's the completed mosaic of Marvin. This one, like Gossamer, has tiles as the background so he sort of jumps out at you a bit. I like the effect a lot but that's a /lot/ of 1x8 tile! :) This piece is 96x96 studs.
Uh, you know what would be some good companion pieces for your Marvin the Martian mosaic? You need to also make ones of K-9, the Cadet, and, of course, DUCK DODGERS OF THE 24TH AND ONE HALF CENTURY! Seriously, nice mosaic.