Very unique piece; we vote for a reduced scale Petard. After all, it has the four rings of most Petards to facilitate moving it and securing it to the castle gate or door with ropes. It also has a vent that appears to be designed for horizontal firing like a Petard in use would be. The base is more like a thunder mug, but it still has more features of a Petard. Maybe a presentation model, much smaller than the real thing, to be presented to the leader of the successful assault troops? Just conjecture here, never saw one like it, ever!!
Tracy and Mike