Exodite War Wagons
The war wagons of the Exodites are an innovation on the ancient chariot, from a culture that did not have horses until recently. Consisting of a horse or ox-drawn covered wagon with a light cannon inside, the chariot has a driver and two gunners. A sturdy wooden wagon capable of holding its ground when a cannon is fired from inside it, the wagon is closed except for a door on the coachbox side and a cannonport to fire from on the side of the wagon. The cannon can be swiveled in a narrow arc, something that also assists in reloading it.
Deploying the war wagons has many challenges, including the requirement to have two horses (or more commonly nowadays, oxen) that do not panic in close proximity to cannon fire. The wagon must carry ammunition, and the gunners must reload the cannon between each shot in a fairly tight space, a laborious task that tires the gunners out surprisingly quickly. Often, these crews rotate the gunners and the driver in prolonged engagements. Though the unit has existed for a few decades now, it has been sparingly deployed. Mostly useful in pitched battles against infantry armies, the wagon is borderline useless in an urban battle or when its flanks cannot be secured. Nevertheless, they have enjoyed some battlefield success in Exodite campaigns against the Valen realms.
Composition
Tactics
The war wagons are used for supporting firepower, the cannons being too light for major siege-work. Usually deployed along the flank, often with some field fortification or obstructing terrain to foul advances and charges against the wagons, the light artillery is used to blast at enemy infantry formations, and particularly archers. Though not incredibly accurate, the cannon blasts will overpower any personal armor or pavise. Such units will struggle to maintain formation and cohesion against the barrage. However, the wagons themselves are difficult to maneuver and require either supporting infantry or terrain obstacles to prevent enemy forces from charging in and taking out the drivers and the gunners.
In response to the prompt Describe a military unit in your world that is famous for its unique ranged weapon.
I guess the horses and oxen need to be trained a little bit so they don't spook at the cannon fire. Cool idea. :D