5e SRD >Creatures >

Swarm of Undead Bats

Family: Swarm

Medium swarm of Tiny undead, chaotic evil

Armor Class 12
Hit Points 22 (5d8)
Speed 0 ft., fly 30 ft.

5 (–3) 15 (+2) 10 (+0) 2 (–4) 12 (+1) 4 (–3)

Damage Resistances bludgeoning, piercing, slashing
Damage Immunities poison
Condition Immunities charmed, frightened, grappled, paralyzed, petrified, poisoned, prone, restrained, stunned
Senses blindsight 60 ft., darkvision 60 ft., passive Perception 11
Challenge 1/4 (50 XP)


  • Echolocation. The swarm can’t use its blindsight while deafened.
  • Keen Hearing. The swarm has advantage on Wisdom (Perception) checks that rely on hearing.
  • 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 bat. The swarm can’t regain hit points or gain temporary hit points.


  • Bites. Melee Weapon Attack: +4 to hit, reach 0 ft., one creature in the swarm’s space. Hit: 5 (2d4) piercing damage, or 2 (1d4) piercing damage if the swarm has half its hit points or fewer.


Undead bat swarms are collections of dead bats that still fly as if they were living, breathing creatures. The bats attack with hundreds of tiny bites as they swarm their prey.

Section 15: Copyright Notice

Tome of Horrors 2020, (C) 2020, Necromancer Games

This is not the complete section 15 entry - see the full license for this page