Fungi: Boom-Shroom:

Deep in the darkness and areas saturated with sulfur and saltpeter there exists a form of fungi known as Amanita eruptio, or more commonly, the Boom-Shroom.  This fungus has a ring and volva on its broad white and faintly black streaked stalk, pink emarginate gills, and a large ovate cap that is purple with black spots on it, and a small concave indentation at the top.  If it is brushed or plucked without first jabbing from the indentation to the stalk, it will swell and explode, spreading its spores in a near sphere, most prevalently on whichever creature or object triggered its response.  These are both capable of living on their native rocky terrain and decaying organic matter, such as a creature killed by the force of the blast.  Most humanoids of medium or larger sizes may be injured by the blast, but rarely killed.  Some creatures are susceptible to fungi and may become moving hosts if their immune system cannot fight off the spores, but most are more than capable if still living.  When growing on a decaying organism or other area without ample sulfur and saltpeter, the black streaks in the stalk are not present, and their concave indentation is much broader.  If one opens a diffused Boom-Shroom, they will find a paste that may be dried out and used as improvised gunpowder for whatever purpose they might need it, as well as the spongy meat of the mushroom, which will be spicy and a little bitter, but quite edible and high in fiber.  A caution though that this meat should be cooked first, as otherwise some of the spores may attempt to inhabit the one that ingested it, causing mild cramps and acid reflux.