A device used by fishermen to set their nets under the ice of frozen lakes. It consists of a plank of wood with an arm on it with a sharp metal tooth on the end of the arm. A rope is tied to the arm which, when pulled, propels the plank along the underside of the ice because the tooth catches the ice. Releasing the rope allows the tooth to sink away from the ice, and when the rope is tightened again, the tooth grabs the ice farther along, allowing the jigger to crawl along the underside of the ice.