Boilerdrak
Large object
Armor Class: 15
Hit Points: 100
Damage Immunities: poison, psychic
Flames. The boilerdrak expels flames in a 60-foot cone. Each creature in that area must make a DC 15 Dexterity saving throw, taking 27 (5d10) fire damage on a failed save, or half as much damage on a successful one.
Explosion. The boilerdrak explodes in a 30-foot radius sphere and is destroyed. Each creature in that area must make a DC 15 Dexterity saving through, taking 27 (5d10) fire damage on a failed save, or half as much damage on a successful one.

This wagon-sized device is designed to look roughly like a dragon. Before it can be used, the boilerdrak must be lit and aimed. It takes 1 action to light the weapon, 1 action to aim it, and 1 action to fire it. When you use your action to fire it, roll a d20. If you roll a 2 or higher, use the Flames action. If you roll a 1, use the Explosion action.