Frostspawn Swarm

Small monstrosity, chaotic evil

Armor Class 13
Hit Points 27 (6d6 + 6)
Speed 30 ft.

STR 8 (-1)
DEX 14 (+2)
CON 12 (+1)
INT 4 (-3)
WIS 14 (+2)
CHA 6 (-2)

Saving Throws Dex +4
Skills Perception +4
Damage Resistances Cold, Necrotic, Bludgeoning, Piercing, and Slashing from Nonmagical Attacks
Damage Immunities Poison
Condition Immunities Charmed, Frightened, Paralyzed, Petrified
Senses Darkvision 60 ft., passive Perception 14
Languages Understands Common, but cannot speak
Challenge 1 (200 XP)

TRAITS

Swarm. The Frostspawn Swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny creature. The swarm can't regain hit points or gain temporary hit points.

Freezing Bite. Any creature that hits the Frostspawn Swarm with a melee attack takes 3 (1d6) cold damage.

Frozen Frenzy. When the Frostspawn Swarm reduces a creature to 0 hit points, it gains temporary hit points equal to half of the damage dealt.

ACTIONS

Bite (Swarm Form). Melee Weapon Attack: +4 to hit, reach 0 ft., one creature in the swarm's space.
Hit: 7 (2d6) piercing damage plus 3 (1d6) cold damage.