Yoric!

Alas poor Yoric, I knew him well!

This one was fast and easy to make, but I loved the result!

Take a skull, any old skull, I happen to have several lying around.  Just grab a shovel and you are bound to "dig up" one or two.

This one happens to be my favorite, labeled Werewolf Skull.

Take a uranium filled marble also called carnival glass.  Check eBay they have them all over.  Get ones that are about 1/2" in diameter and without any design or pattern.
Add a UV Led.  Also can be found on eBay.  But I will add another source as soon as I find it again.  I got these wired to a small control board that pulses them on and off or can cause them to blink rapidly.
Plop'em in the eye sockets and there ya go.  Ok there more to it then just this, but you can understand the effect.  I actually installed the LED's from behind and hot glued them into place, then added the marbles and hot glued those also into place.  The control board and 9Volt battery are actually in the base of the skull, I cut it opened to install the LED's.