Nicely done. Great sculpt, and terrific Photoshoppery to get the color in there. It might be nice to put Dave’s link on the image as well, just like you did with your own. Good work like this spreads fast on the internet and there might come a day where Google Image Search will be serving up your render alongside Dave’s originals and you can guess how that might feel.
Maybe you asked for permission to do this, maybe not. Most of the time illustrators are pretty pleased when someone sculpts up an image, but it’s always polite to ask.
Anyway - excellent work, is it watertight? Can it be printed? Are you going to make a base?