“ The bloated corpse of a decaying gigantic creature is necromatically enhanced and fused with an undercarriage for use as a grisly and terrifying airship. The methane gas from tissue decay keeps it buoyant in atmosphere, but it can be even more flammable than hydrogen if it escapes...”
“ A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.”
“ A city is being plagued by a swarm of winged mice. The vermin can get anywhere, and they can easily avoid their normal predators by simply flying away from them.”
