The Kolibri (German for "hummingbird") is the smallest commercially available centerfire cartridge pistol and was introduced in 1914 by Franz Pfannl, a watchmaker. About a thousand of these tiny pistols were made between about 1910 and the beginning of World War I in 1914, when production had to stop as the economy turned to a war footing. Though perhaps considered a novelty, it may have still been effective when used to deter stray dogs—a common use for miniature pistols of the era.
The weapon's small size makes it difficult to handle and reload, with the 2.7mm cartridges themselves being fairly underpowered. Due to technology at the time being incapable of applying rifling to the bore of such as small caliber, bullets do not spin when fired, greatly affecting accuracy.
— In-game description
The smallest weapon in the game, the Kolibri is more of a novelty rather than being an effective sidearm. Due to the tiny caliber of the bullets, the weapon has an extremely low damage output, and only truly serves a purpose as a means of humiliating enemies who are unfortunate enough. It has low accuracy due to the difficulty in its handling, but also negligible recoil. This is showcased when holding the weapon as it is only held with the thumb and forefinger.
Due to its low damage output, the best way to obtain a kill with the sidearm is to only fire at heavily damaged enemies. This can be done in combination with the player's primary and taking note of the enemy players health. Despite this, the Kolibri is, however, capable of killing infantry with one magazine through a series of headshots at close range, each inflicting up to 25 damage. It functions somewhat effectively alongside the other Scout rank 10 unlock, the Martini-Henry; as a single shot from close range will leave your target with 10hp, enough to secure a kill in three to four hits.
- When switching to the Kolibri for the first time, the character presents the weapon in his palm, and seems surprised at its size. Though brief, this animation may yet cause unfortunate delay.
- In the loadout customization screen, if the player selects the Kolibri as a secondary weapon, the character will look at the weapon (being held with his right hand) with surprise. Usually, with the other secondary weapons, the character looks straight into the camera.
- Though the first-person view shows the character holding the Kolibri with one hand, third-person view while crouched shows the character using their left index finger as a rest.