This new prop was designed to look like this Creepy Coffin commercial prop. When I saw it online and in the stores, I liked the concept and the look. However the commercial version was static and made of Styrofoam. And it cost $99.
Instead of buying that prop I took the money and built this 6-foot animated version. It uses a wiper motor to open and close the hinged front. The outside chains and lock are plastic and foam but inside there are five pieces of real chain swinging and banging. A couple of ACC arms replaced the foam ones on the commercial version. It cost me less than $100 to make and will outlast the commercial version by many years.
Here's a picture. A how-to project description will be posted next month. Here's 10-second video clip showing the motion.