Gyrocopter

Some dwarves have crafted strange machines they call 'Gyrocopters'. Capable of flight, they need space to manoeuvre, thus they cannot be used underground. Gyrocopters are hard to control and are not suited to close combat. Instead, their drivers throw strange eggs they call 'bombs', that explode with the sound of thunder. None know what strange beast lays such eggs.

bomb frapo

10 - 2 distance