Medium Elemental, unaligned
Armor Class 12
Hit Points 40 (9d8)
Speed fly +30, walk +10, climb +10
Challenge 2
Skills perception +0
Damage Resistances bludgeoning, piercing, slashing
Damage Immunities cold
Condition Immunities charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
Senses passive Perception 10
Languages —
False Appearance. While motionless indistinguishable from cluster of icicles. This trait doesn't function if swarm has damaged a creature with blood within the past 2 hrs.
Frigid Mass. A creature that starts its turn in the swarm's space takes 4 (1d8) cold.
Heatsense. The swarm can pinpoint the location of creatures emitting heat such as warm-blooded Beasts and Humanoids within 30' of it.
Spider Climb. Difficult surfaces even ceilings no ability check.
Swarm. Can occupy another creature's space and vice versa and swarm can move through any opening large enough for a Tiny elemental. Can't regain hp or gain temp hp.
Impale. Melee Weapon Attack: +4 to hit, 0 ft., one creature, in the swarm's space. 7 (2d6) piercing damage + 9 (2d8) cold or 3 (1d6) piercing damage + 4 (1d8) cold if the swarm has half its hp or fewer.
Source: Tome of Beasts 3 · OGL/Open