This is a very inexpensive project and a great intro to electronics.
This build is completely based off of Bigant's Monster in a Box which he posted here.
I used all the same electronics but instead of an opening box I've got a quivering corpse.
Speaking of the corpse, the pvc 'skeleton' that you see is made from plans and parts from Spider Hill Prop Works (thanks Diabolik!). I'm going to flesh him out with some metal fabric (similar to chicken wire but with a tighter weave) and have his guts hanging out. I'm going to use great stuff to make the guts. I haven't yet decided if he's going to have legs or if something has ripped them off and eaten them.
I used the hardware that came with the door lock actuators to attach the actuator to the base, and a simple zip tie to attach the actuator to the body. You can see the actuator has plenty of power to move the body around for this purpose.