A sleeve- gun is an apparatus which conceals a small firearm under a long sleeve. A triggering mechanism causes the weapon to extend out of the sleeve quickly enough for the user to grab hold and fire. Initially used in military contexts, the device has become popularized in various media; Christolph Waltz uses one on Leonardo DiCaprio in Django: Unchained, Jim West from Wild, Wild West had one, “Christie” from Alien Resurrection has two, etc.
Sleeve-gun in action in “Django: Unchained”
Can you own one? No. As you probably guessed from the title of this article, this sort of weapon is prohibited for sale in Canada. Any handgun designed to be concealed in the palm is. There must be some out there re-appropriated with a comb or toothbrush or something, which is almost as good I guess.