Hungry? Scare those fridge-bound famished food foragers with a head in a jar! Using a photo editor, two pictures are blended together to create flat image of a head, which is then laminated and submerged in a jar. When the flattened image in inserted into the curved jar, along with the distortion from the water, gives the illusion of a decapitated head in a jar of preserving fluid. Click the source link to read the full article. Source (Instructables): http://www.instructables.com/id/head-in-a-jar-prank/?ALLSTEPS