Yellow mold was a toxic fungus that spread in dim, hidden places, coating stone or wood in irregular patches. Each growth covered a small area, yet posed a serious threat to the careless. When touched or disturbed, the mold erupted in a sudden cloud of spores, filling the air in a choking burst. Those caught within often found their lungs seared with poison, weakening their bodies and leaving them reeling as the toxins continued to burn from within. Even a brief exposure could prove deadly, making old ruins and forgotten tunnels laced with yellow mold dangerous to explore.
The fungus was fragile once its weakness was understood. Sunlight withered it to nothing, and even the smallest spark of flame could burn it away. For this reason, experienced adventurers carried fire into places where yellow mold might lurk, though caution was always needed, since disturbing the mold before destroying it could trigger a poisonous outburst. To the unprepared, yellow mold was as lethal as any trap, its drifting spores lingering as a silent threat in the air long after its discovery.