Wizard Sponge

This strange type of fungus colony takes its name from its initial purpose: the wizard who first developed it sought a means to keep her tower clean from residue both mundane and magical. Wizard sponge does just that, dutifully cleaning its vicinity by devouring dust, organic debris, and even the decaying bodies of fallen creatures. Its designer intentionally crafted the fungus to not merely resist but be healed by fire, intended as an additional safety feature, and most varieties have a convenient side effect of being edible once slain. Unfortunately, the fungus also developed an unexpected ability to magically mutate over time, which eventually led to its escape and independent propagation.

Wizard sponge colonies of various sizes and shapes now thrive in dungeons, caverns, sewers, abandoned castles, crypts, and even the basements of some occupied dwellings. They often carry along bits of partially consumed material with them, such as clothing, limbs, and adventuring gear-sometimes even valuable treasures! An individual colony typically takes on distinctive properties based on what it's consumed in its environment; a variety living in a necromancer's crypt might acquire the undead's affinity for void energy, for example.