The revolting Mutant is the surprise result of a symbiosis between a Sprout and a human corpse. A Sprout finds a lifeless body and grows its stems through the flesh, penetrating the brain and taking control of the dead body’s motor functions in under a minute.

The hybrid is fully submissive to the Sprout and can either move on two legs or hover using propeller leaves.

Different Sprout versions do different things to corpses, turning them into a variety of hideous monsters, from incredibly quick and agile hybrids to clumsy hybrids possessing enormous strength.
You are better off eliminating Sprouts before they can turn poor dead people into the stuff of nightmares.