kolibri
Also known as the 2.7mm Kolibri Car Pistol, chambered in a proprietary 2mm cartridge. Its name is German for "hummingbird". It was patented in 1910 and introduced in 1914 by Austrian watchmaker Franz Pfanni. Production quickly halted soon after due to World War I, eventually discontinuing by 1938.
Notoriously known as one of, if not THE smallest firearm in history. While advertised to be a self-defense weapon for women, its usefulness was highly questionable due to the combined lack of accuracy, pathetic stopping power, and unwieldy design.
Gained some renewed infamy due to its inclusion in Battlefield 1 as an unlockable weapon for the Scout kit, though its laughable in-game performance firmly cemented it as a joke weapon.