The Head Zopper illusion is an illusion in which it appears that the magician has sawn through someone's neck with a saw. It is usually performed on an audience volunteer, rather than on a professional assistant.
The apparatus used for the illusion resembles that used in the Jig Saw illusion, with a set of stocks designed to accept the blade of an electric jig saw. However, in the Head Zopper, the hole in the stocks is much smaller than in the Jig Saw illusion. In the Jig Saw, the hole is designed to fit around the waist of the "victim", whereas in the Head Zopper it fits around their neck. Also, the Head Zopper stocks are mounted on a set of legs that allow the "victim" to kneel behind them and lean forward to place their neck into the hole in the stocks.