This is a veary simple and cheap progect for a somewhat complicated and expencive prop.
~6 pieces of 1" x 2" wood about the lenth of your forearm
~some type of plywood base, or something that will hold it down
~at least two small hinges, if not more, or something like string or wire that will hold the joints together and still allow some movement
~mask or skull
~something to hold the head on or a small peice of pvc
~a few bolts, washers, screws, and nuts
First you will want to measure the pieces of wood to the lenth of your forearm and upper arm for both arms of the ground breaker and then one lenth of wood that is about the width of your shoulders the sixth one is for a support.
Next attach each peice of wood as shown below in pic 1.
When your all done then you can stick a head on the pvc and dress it up in some creepy clothes.