Hellwasp Swarm

Hellwasps' infernal nature allows them to collectively inhabit and control humanoid corpses, and they use this ability to infest and horrify large swathes of territory unless destroyed. While individual hellwasp poses little threat, these fist-sized insects instinctively form into aggressive swarms that will viciously attack any creature approaching their colony, the lone exception being powerful fiends.

Hellwasp swarms have a rudimentary intelligence focused on the protection and expansion of their colony. They can understand Infernal but are incapable of speech. They sometimes obey simple commands from a lawful fiend more powerful than their swarm, but there is no nuance or understanding to this obedience, and if left alone for more than a day they stop obeying and return to their colony.