SRD (p.384)
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 insect. The swarm can't regain hit points or gain temporary hit points.
Bites (swarm has more than half HP). Melee Weapon Attack: +3 to hit, reach 0 ft., one target in the swarm's space. Hit: (4d4) piercing damage. Bites (swarm has half HP or less). Melee Weapon Attack: +3 to hit, reach 0 ft., one target in the swarm's space. Hit: (2d4) piercing damage.
Created for Dungeon Masters and Game Masters, World Anvil has everything you need to build your own homebrew RPG campaign setting, and run your games, either online or around the table!
Take the first step. Create your account. Your world and characters await!