A trap-monster swarm of endless flaming ants that pours from a booby-trapped reward suitcase and burns car five to ash.
Literal Fire Ants are the trap-monster (level 1) hidden inside Princess-Donut's number-eight reward suitcase — 'like regular fire ants, but with more enthusiasm,' and they 'hate you and want you to die.' The moment Carl cracks the zip (his Find Traps skill flashing a first-ever warning), thousands of flaming ants surge out — far more than the bag could hold — igniting everything, detonating Vernon's moonshine, and engulfing car five. They kill the conductor Vernon, burn Princess-Donut's tail, and force the party to flee onto a platform as the flames consume the car and the mobs in it.
An unending, fast-spreading swarm of ordinary-looking ants wreathed in flame, igniting every surface they cross.
A booby-trap swarm that turns a 'prize' into a car-destroying inferno and kills Vernon.