Yellow Mold

[The Archivist]

A deadly underground fungus which can be exterminated only by fire. It attacks wood and flesh -- doing one die of damage if it contacts exposed skin -- but does not harm to metal or stone. However, its worst threat is its spores. Rough contact with Yellow Mold will have a 50% chance of causing it to break and send forth clouds of asphyxiating spores in a 1" x 1" X 1" cloud. Any creatures within the spore cloud must make saving throws as if they had been exposed to poison, and failure to make saving throws results in death for the parties concerned.

I run this as one die of damage per melee round and that the spores burst into growth on contact with lung tissue. Making the saving throw means that instant death does not occur; however, Cure Serious Wounds Must be cast immediately on each exposed person to prevent death from occurring within two turns.