Armor Class 10
Hit Points 24 (7d8 - 7)
Skills stealth +2
Damange Resistances Bludgeoning, Piercing, Slashing
Damage Immunities Necrotic
Condition Immunities Charmed, Frightened, Grappled, Paralyzed, Petrified, Prone, Restrained, Stunned
Smell The swarm has advantage on Wisdom (Perception) checks that rely on smell.
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 rat. The swarm can’t regain hit points or gain temporary hit points.
Blood Baiting If blood is present within 30 feet of the swarm and it is not currently within melee range of a living creature, the swarm will use its movement to move to the location of the blood.
Bite Melee Weapon Attack: +2 to hit, reach 0 ft., one target in the swarm’s space. Hit: 7 (2d6) piercing damage plus 7 (2d6) necrotic damage, or 3 (1d6) piercing damage plus 3 (1d6) necrotic damage if the swarm has half of its hit points or fewer.
Lair and Lair Actions
Frenzied Swarm When encountered in their lair, swarms of undead rats are attracted by the activity of other undead rats. At the start of each round, so long as one or more swarms of undead rats are present, roll 1d6. On a five or six, another swarm of undead rats appears within 5ft of an existing swarm.