Shaking Crate
One of the effects that I worked on for the Creepshow Maze at Universal was this shaking crate. The effect was to appear as if there were a creature inside trying to get out. To achieve this, I created a spring mounted mechanism with a handle that attached to the backside of the crate to allow an actor to motivate it. In order to have it look less like a bobble head, we added a spring to each corner of the box as well which allowed it to shake more abruptly.