Sources
CR
Type
Size
Alignment
Movement

Skeletal Swarm

Large swarm of Medium Undeads, Lawful Evil

Armor Class 13 (armor scraps)
Hit Points 60 (8d10 + 16)
Speed 30 ft.
STR
12
+1
DEX
14
+2
CON
15
+2
INT
6
-2
WIS
8
-1
CHA
5
-3
Damage Vulnerabilities bludgeoning
Damage Resistances slashing, piercing
Damage Immunities poison
Condition Immunities Charmed, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned, Prone, Restrained, Stunned
Senses darkvision 60 ft., passive Perception 9
Languages
Challenge 2 (450 XP)

Traits

Deafening Clatter. Creatures are deafened while in the swarm's space.

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

Actions

Slash. Melee Weapon Attack: +4 to hit, reach 0 ft., one target in the swarm's space. Hit:11 (2d8 + 2) slashing damage, or 6 (1d8 + 2) slashing damage if the swarm has half of its hit points or fewer.

Lore

This swarm of bones found rising out of the sand in Isle of the Abbey is made from the remains of several animated skeletons. A skeletal swarm alternates its appearance between partially formed humanoid shapes and a chaotic, swirling mass.