Bomb Beetles

A type of Giant Creature resembling a bomb beetle that appears side by side with Storm Ants.
Regular bomb beetles typically release high-temperature gas as a means of escaping from enemies,
but these giant Bomb Beetles ignite internally created gas via friction with their abdominal shell to use as a means of propulsion, or as a flamethrower-like attack.

After being killed, gas leaked from their carcasses can ignite to create a large internal explosion, so soldiers must always stay cautious when nearby.
Their gas is so vile in smell as to be harmful to humans.
Due to this, even after the flames subside, areas where Bomb Beetles have trodden are difficult to rebuild due to contamination.