Slimes, Mold and Fungi
From AmtWiki
Another popular element of fantasy dungeoneering: the limitless variations of algae, mold, slimes and oozes ever-present in caves, caverns and other underground environs. Such basic life forms come in an amazing variety, each suited for the particular niche it has managed to carve out for itself.
To place some in your dungeon, mark off an area with appropriately colored ribbon, preferably close to the ground. What any particular mold does it left to your imagination, but a few of the more common types include the following: Category:Slimes Molds and Fungi