Ghost Shrooms appear as a patch of black mushrooms growing underground. A conical cap sits upon a main stalk from which mycelia extend to smaller stalks, which might be as far as 20 feet from the main stalk. The largest stalk stands three feet tall.

This fungus is strange, seemingly a natural living group of mushrooms but behaving and being detected as a form of undead. Indeed, ghost shrooms can subsist only on dead flesh, which they collect by entangling and constricting living beings until unconscious and then infiltrating them with strands of mycelia (the fungal equivalent of plant roots).

Though a group of ghost shrooms is technically a single entity, the main stalk and each subordinate stalk are given their own hit dice and hit points. Destroying a small stalk does not affect the rest of the patch, but destroying the main stalk results in the smaller stalks ceasing to attack for 1d4 rounds. Entangled creatures are still held but the per-round damage is not applied for this duration. Then, one of the remaining stalks becomes the main stalk (though its statistics do not change right away) and the patch resumes hostilities. If the ghost shroom patch survives such a confrontation, the new main stalk will gain 1 hit die per week until it reaches 4 hit dice. New small stalks can be spawned at a rate of one per month any time the main stalk has its full 4 hit dice.