Curse of Strahd
The Flame Gun
This “gun” spits a sticky concoction of green flame, and works like a burning hands spell cast at 9th level. It therefore does 12d6+32 damage in a 15-foot cone.
Each creature in that 15-foot cone must make a Dexterity saving throw. A creature takes the full 12d6 fire damage on a failed save, or half as much damage on a successful one. It also does double that damage to objects and structures made of wood.
It is cumbersome and must charge through priming the pump for at least a round before firing. There is also a 25% percent chance of misfire.
The device generates so much heat after a six second blast that it must cool for at least 12 hours between firing again. The amount of fuel that it expends is equal to 1/6 the full tank.