Swarm of Bats
Creature
A Swarm of Bats is less a deadly thing than a maddening one: a shrieking, wheeling cloud that erupts from a cavern roof and fills the air with leather and noise, fouling torches, spoiling bowshots, and clawing at the eyes until a party can barely tell which way is out. The bites are small. The chaos is total, and many a careful expedition has come to grief not from the swarm itself but from what found them while they flailed blind in the middle of it.