Swarm of Bats

Swarm of Bats CR: 1/4

Medium swarm of tiny beasts, unaligned

Armor Class: 12

Hit Points: 22 5d8

Speed: 0 ft , fly: 30 ft

STR

5 -3

DEX

15 +2

CON

10 +0

INT

2 -4

WIS

12 +1

CHA

4 -3

Damage Resistances: Bludgeoning, piercing, slashing

Condition Immunities: Charmed, exhaustion, grappled, paralysed, petrified, poisoned, prone, restrained, unconscious.

Senses: Blindsight 60ft, passive Perception 11

Challenge Rating: 1/4

Echolocation. The swarm can't use it's blindsight if 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.

Actions

Bites. Melee Weapon Attack +4 to hit, reach 0ft, one creature in the swarm's space. Hit 5 2d4 piercing damage, or 2 1d4 piercing damage if the swarm has half of it's hit points or fewer.

A swarm of bats is very rare thing. Usually only encountered where they roost, it is likely been called forth by a creature like a vampire or by magic.

Suggested Environments

Forests, hills, settlements, riverbanks.