Yellow Mould
by Jamie BatyBA, RC 213
(CR 6): This dungeon peril is a dangerous variety of fungus. Yellow mould devours wood, leather and other organic materials but does not harm metal or stone. Bright yellow, and powdery, it clings to walls, floors, and ceilings in patches, reproducing as it consumes organic matter. It releases spores when it detects movement (and possible food) or is disturbed. Even the hardiest adventurers will succumb to the mould and its deadly spores if multiple patches are repeatedly disturbed.
Yellow mould covers an area in 10ftx10ft square patches. Often there are up to 1d8 patches in an affected area. Each character disturbing (by movement, attack, damage-causing spell, etc...) a 10-foot square of yellow mould must make a Reflex save vs DC15. A failed save indicates a 10ft x10ft x 10ft spore cloud is released. Any creature caught in the cloud suffers 1d4 damage from the spores attacking its flesh, and suffers 1d8 non-lethal damage from choking and difficulty breathing each round they are in the cloud. A cloud lasts two rounds and any spellcasting while in the cloud requires a DC 15 Concentration check. A patch of yellow mould may release up to 4 spore clouds per round, and the effects are cumulative.
Anything or attack that causes more than 2 hp of fire damage can destroy a patch of yellow mould. It takes a full round action to destroy a patch of yellow mould with fire. Area attacks such as a fireball will successfully remove all yellow mould from its area of effect.