False Appearance: While the swarm remains motionless, it is indistinguishable from an ordinary patch of fungus   Sporeburst: When the swarm takes bludgeoning, force, piercing, slashing, or thunder damage, it releases puffs of necrotic spores. Each creature within 5 feet of it must make a DC 13 DEX saving throw, taking 2d8 necrotic damage on a failed save, or half as much damage on a successful one.   Swarm: The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny mushroom. The swarm can't regain hit points or gain temporary hit points.