Corpse Puffs

Corpse puffs are a dangerous species of fungi which prefers to grow on and around dead fauna.

Description

A single corpse puff can reach seven inches in height, the cap is inverted and forms a vase-like structure with a small opening at the top. It's stem a pale light green, the cap starting as a dark green at the stem and fading into a bright green at the edge and the gills within the are a bright yellowish green.
Corpse puffs are typically seen growing singly or in small groups. However, if there is sufficient decaying material, such as a large corpse, a much more dangerous fungi colony called a Corpse Tree may form.

Spores

These fungi are no different than typical mushrooms in terms of biology and how they reproduce. On key difference, however, are their spores and it is these that make them so dangerous.
Normally, these spores when they land on a surface will lay dormant until a dead body or similar source of biomatter (such as a pool of blood) comes into contact with them, at which point they will eventually grow into either a single or a small group of corpse puffs, depending on the size of the food source. If spores are inhaled by a living creature, they will immediately attach to the cell walls of the respiratory system and begin to grow, causing irritation and the victim starts to cough. The coughing draws in more spores and the cycle repeats, until the victim is no longer able to breathe and collapses, usually not far from where the first spores were inhaled.
If the affected is able to get away from where they spores were inhaled quickly enough, they will eventually recover, albeit with some permanent damage to their respiratory system. Otherwise, a domino effect may occur: predators and scavengers tempted by a free meal fall prey, as would any sapient beings that try to rescue their fallen fellows. This risks building a literal dead zone populated only by plants and fungi, with the most numerous being the corpse puffs with at least one corpse tree. These areas can become so thick with spores that they become uninhabitable for fauna until either rain washes them away or fire destroys them.

Preventing Dead Zones

There's no easy way to prevent a corpse puff take over. Mature corpse puffs release spores at the slightest touch and water can inadvertently spread them over a wider area. Managing the dead, both animal and Daulka is the only effective means of controlling their spread. Ensuring any remains are either completely dried/used or burned is the only way to prevent corpse puffs from taking hold. Indeed, it is this prevention measure that resulted in the Daulka tradition of burning the dead via Sending rituals, even in regions where Corpse Puffs can't survive.