Lesson learned:  When you create an animated monster mud prop, always leave yourself an access panel to re-set the gears and reattach the wires.  Storage plays hell with wooden gears.

Pics below the fold. 

Here is my imp, open and missing his head.

The bar connecting the motor to the flywheel came off over the winter, and the leds in the eys came loose.

Here he is, back together and working:

The wound is still a bit raw in this picture.  A light dusting of flat black spray paint fixed that.