Swarm of Piranhas
Medium beast, unaligned
Armor Class 13 (natural armor)
Hit Points 28 (8d8 - 8)
Speed 5 ft., swim 40 ft., climb 2 ft.
str
13 (+1)
dex
16 (+3)
con
9 (-1)
int
1 (-5)
wis
7 (-2)
cha
2 (-4)
Senses darkvision 60 ft., passive Perception 8
Languages -
Challenge 1 (200 XP)
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 piranha. The swarm can't regain Hit Points or gain Temporary Hit Points.
Water Breathing. The swarm can breathe only underwater.
Actions
Bites. Melee Attack Roll: +5 (with Advantage if the target doesn't have all its Hit Points), reach 5 ft. 8 (2d4 + 3) Piercing damage, or 5 (1d4 + 3) Piercing damage if the swarm is Bloodied.