The skull part only from http://www.thingiverse.com/thing:33510. Add to what ever you wantI printed this with the same settings as http://www.thingiverse.com/thing:33510 and got pretty good results. I suppose you could do some fancy stuff like smaller nozzles and smaller layer heights. Use the 30% scaled skull for a normal prusa print, the regular skull is enormous, unless that's what you want.