"Incendiary-shot mini-artillery device. Mechanoid-built."
The Inferno Cannon is a siege weapon typically wielded by Mechanoid centipedes. Doesn't drop on death, making it Mechanoid-only.
The primary danger of the cannon is not killing, but covering your colonists in burns that may scar badly, or putting them into shock and incapacitating them due to the pain of the burns, as well as create a large blast that will start fires.