Be scared! I’ve made four of these; one of them is a bit bigger than the two you see below. Each doll is powered by a 9V battery, and I installed a switch in the back of all but one of their heads.

Here they are with a bit of light. (Click the image for a really big view.)

Here they are with less light. (Click the image for a really big view.)

Finally, here’s a video of them in action.