Large Fey (Swarm), chaotic evil
Armor Class 14
Hit Points 110 (20d10)
Speed fly +40, walk +10, hover true
Challenge 10
Skills perception +6
Damage Resistances bludgeoning, piercing, slashing
Condition Immunities charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
Senses darkvision 60 ft., passive Perception 16
Languages Sylvan
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 nyctli. The swarm can't regain hp or gain temporary hp.
Innate Spellcasting (1/Day). The nyctli swarm can innately cast fear, requiring no material components. Its innate spellcasting ability is Charisma.
Stingers. Melee Weapon Attack: +8 to hit, reach 0 ft., one target in the swarm's space. Hit: 21 (6d6) piercing damage, or 10 (3d6) piercing damage if the swarm has half of its hp or fewer. The target must make a DC 16 Constitution saving throw. On a failure, a creature takes 42 (12d6) necrotic damage and is blinded for 1 minute. On a success, a creature takes half the damage and isn't blinded. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Douse Light. As the nyctli, except the swarm can't dispel light created by a spell of 6th level or higher.
Source: Tome of Beasts 2 · OGL/Open