I got this idea from...the internet somewhere.
We learned about dinosaurs a couple weeks ago, and for one of the activities Little Boy and Isaac made "fossils."
We smashed some playdough onto the table to represent mud. The idea was to stick dry pasta--representing dinosaur bones--into the playdough to make a dinosaur shape.
Little Boy started out that way--you can see a head, neck, and arms...and maybe legs...in the photo there. But then he apparently decided that wasn't 3-D enough for him. Oh, well. We weren't really going for accuracy.