Abstract: A practical joke device comprises a mouthpiece attached to a rolled-up (or deflated) display portion. The display portion can be unrolled (or inflated) and thereby extended by delivering air thereto by way of the mouthpiece, in order, in use, to display information carried thereon. The display portion comprises a panel adapted for carrying and displaying information. The panel has such size and dimensions that, in the unrolled, extended (or inflated) state at least one dimension of the panel is about 3 or more times greater than the width of the mouthpiece. The at least one dimension is generally transverse to the extension direction of the display panel. In the unrolled, extended (or inflated) state, the extension direction of the display panel may be displaced from the axis of the mouthpiece.