b'Infernal Swarm \n'b'  Huge swarm of Small   fiends  (devil),  lawful evil  \n'b'  Armor Class  16 (natural armor)  Hit Points  150 (20d12 + 20)  Speed  25 ft., fly 40 ft. (hover)\n'b' STATS STR: 18 (+4) DEX:  16 (+3)  CON:  13 (+1)  INT:  8 (-1)  WIS:  12 (+1)  CHA:  19 (+4)  \n'b'\n'b'\n'b'\n'b'\n'b'\n'b'\n'b'  Damage Vulnerabilities  thunder  Damage Resistances  bludgeoning, cold, piercing, psychic, slashing  Damage Immunities  fire, poison  Condition Immunities   charmed ,  frightened ,  paralyzed ,  petrified ,  poisoned ,  prone ,  restrained , stunned  Senses   darkvision  120 ft., passive  Perception  11  Languages  understands Infernal but can\xe2\x80\x99t speak, telepathy 60 ft.  Challenge  12 (8,400 XP) \n'b' Special Traits \n'b'\n'b'  Devil\xe2\x80\x99s Sight . Magical  darkness  doesn\xe2\x80\x99t impede the infernal swarm\xe2\x80\x99s  darkvision  \n'b'  Magic Resistance . The infernal swarm has advantage on saving throws against spells and other magical effects. \n'b'  Shaped Swarm . As a bonus action, the swarm can shape itself into a Huge fiend or back into a shapeless mass. Its statistics are the same in each form, and it can\xe2\x80\x99t regain  hp  or gain  temporary hp . If a creature is more than 10 feet away from the infernal swarm, it must take an action to visually inspect the fiend form and succeed on a DC 25  Intelligence  ( Investigation ) check to discern the Huge fiend is actually a swarm of Small insects. A creature within 10 feet of the swarm immediately discerns the truth. While in fiend form, it can wield weapons and hold, grasp, push, pull, or interact with objects that might otherwise require a more humanoid form to accomplish. If the infernal swarm takes thunder damage while in its fiend form, it immediately changes to its shapeless form. While in shapeless form, it can occupy another creature\xe2\x80\x99s space and vice versa and can move through any opening large enough for a Small fiend, but it can\xe2\x80\x99t grapple or be  grappled . \n'b'\n'b' Actions \n'b'\n'b'  Multiattack . In fiend form, the infernal swarm makes three attacks: two with its scimitar and one with its slam, or three with its scimitar. In shapeless form, it makes three attacks with its bites. \n'b'  Bites (Shapeless Form Only) .  Melee Weapon Attack : +9 to hit, reach 0 ft., one target in the swarm\xe2\x80\x99s space.  Hit : 28 (8d6) piercing damage, or 14 (4d6) piercing damage if the swarm has half its  hp  or fewer. \n'b'  Poisonous Barb .  Ranged Weapon Attack : +8 to hit, range 30/120 ft., one target.  Hit : 10 (2d6 + 3) piercing damage, and the target must make a DC 17  Constitution  saving throw, taking 18 (4d8) poison damage on a failed save, or half as much damage on a successful one. \n'b'  Scimitar (Fiend Form Only) .  Melee Weapon Attack : +9 to hit, reach 10 ft., one target.  Hit : 14 (3d6 + 4) slashing damage. \n'b'  Slam (Fiend Form Only) .  Melee Weapon Attack : +9 to hit, reach 10 ft., one target.  Hit : 18 (4d6 + 4) bludgeoning damage, and the target is  grappled  (escape DC 17). Until this grapple ends, the target is  restrained , and the infernal swarm can\xe2\x80\x99t slam another target. In addition, at the start of each of the target\xe2\x80\x99s turns, the target takes 14 (4d6) piercing damage. \n'b'\n'b' About \n'b' A towering winged devil looms above, a wicked scimitar in its grasp. Its form shifts subtly, hinting at a deeper secret. \n'b'  Infernal Insects . Infernal swarms are found throughout the Hells. Considered a delicacy, these insects can form a hive mind, which they use to shape their swarm into a massive winged devil whenever they are threatened. The individual insects are bat-winged and have bulging eyes, long spindly legs, and a carapace covered in poisonous barbs. \n'b'  Hellish Poison . Infernal swarms feed on carrion, injecting the carcasses with a poison that liquifies tissue. This same poison coats their barbs, which painfully dissuades predators. \n'b'  Sensitive to Sound . Loud noises disorient the insects and interrupt their coordination, temporarily scattering the individuals. However, it is rare to encounter these silent killers hunting on their own, and if one is spotted, there are certain to be many more to follow.'