I made one with out the connectors for the bones. This was printed on a Replicator 2, 0.2mm. I printed with support, but it might print ok without it. You can find the files here: http://www.thingiverse.com/thing:506278
Nice idea.Turned out great! Thanks for sharing!
Looks good. Supports are required for the bottom lip of the main body, but not the skull cutout, the curve is easily bridged if your printer is setup well. Also the top can be printed without supports, just rotate it to sit on one of its 45º faces.
The top also prints without support if you build it upside-down.