Bat Swarm

Creature statistics
XP Value 25
Treasure Nil
Type Beast - Animal
Size Small
Climate/Terrain Caves, Ruins, Subterranean
Frequency Common - Night or Dark
Number Appearing 3d6+1
Movement Speed Fast (Flying)
Hit Points 1
Defense Score 2
Defense Target 5+
Melee Attack Score Bite/Claw 2
Attack Target 5+
Tactics Swarm
Immunity Charm, Fear
Resistance None
Weakness None

"A churning cloud of leathery wings and high-pitched screeches, the bat swarm moves as one; erratic, yet eerily coordinated. Individually, bats are relatively harmless, but together they obscure vision and harass foes with endless attacks from their claws and teeth. They burst from the ceiling like living shadows, driven by hunger or their disturbed slumber..."

...from the Wyrmbrand's Monstrous Archive entry 'Bestia Nocturna'

Attributes

Ability scores
STR3 (2)
VIT1 (1)
DEX4 (2)
INT1 (1)
WIS1 (1)
CHA1 (1)
Additional scores
Initiative2
Awareness1
MoraleN/A