It was my son's idea to create a dinosaur skull that would sing jingle bells. This is the result of that project. The bottom jaw is controlled via a servo mounted in the base.

In this video you can see the skull in action singing jingle bells.
http://youtu.be/Z-ojvIRqI_Q

Undubbed with circuit board visible
http://www.youtube.com/watch?v=0hoYsfMroyg

I assembled the skull by brushing the surface with acetone, and then connecting the pieces together and securing it with rubber bands. I dissolved scrap abs plastic pieces in a jar with acetone overnight. I then added glow in the dark pigment to the abs and acetone mixture. I really like the texture that this gives when dry, its a very bone-like texture. After the skull is finished how you wish carefully cut the bottom jaw from the upper piece. I finished the bottom box by brushing with acetone the sanding smooth. I used oil paints to try and give it a wood look. I used acetone as the medium for the oil paints. This worked quite well and I will be exploring using oil paints on abs more in the future. I gave it a few coats of spray lacquer to make it shiny. The bottom jaw connector is printed in two pieces join the two pieces by brushing with acetone. Connect wire to jaw pivot(see photo). Connect the stand skull mount to the bottom of the upper skull. It is helpful to brush the surface well with acetone letting it get nice and gooey. It should fit nice and flush with the obtrusion in the back of the upper skull. Connect the bottom pivot stand piece to the top. Connect the bottom jaw pivot to the lower jaw. Assemble rest of the stand. The bottom stand part pushes through the bottom of the box. Install servo motor in the bottom of the box. Cut wire to length and connect to servo.