This cave has hindered Nezznar's explorations. The drow suspects that the mine's magic workshops are close by, but he's reluctant to risk dealing with the monsters here.
Dense carpets of weird fungi cover large sections of the floor in this cavern. The growth includes puffballs a foot across, weird shelf fungus growing on stalagmites, and large stalks and caps a good five feet tall. Some of the puffballs glow with an eerie green phosphorescence.Most of the fungi is harmless, and the green-glowing fungi allow creatures to see the entire cavern without the aid of darkvision or a light source.
Poison Gas. Whenever a creature attempts to cross the cavern, the carpets of fungi that cover most of the floor release poisonous gas into the air. Each creature in the cavern must succeed on a DC 11 Constitution saving throw or take 3d6 poison damage and be poisoned for 10 minutes. The gas disperses after 1 minute, but until then, any living creature that ends its turn in the cavern must repeat the saving throw.