Cat Swarm

Family: Felines

The silent rippling muscles of the clowder slip by unnoticed until nothing remains but gnawed bones and fat stomachs.

Huge swarm of Tiny beasts, unaligned

Armor Class 14
Hit Points 55 (10d10)
Speed 40 ft.

9 (-1) 18 (+4) 10 (+0) 2 (-4) 14 (+2) 3 (-4)

Skills Stealth +6
Damage Resistances bludgeoning, piercing, slashing
Condition Immunities charmed, frightened, paralyzed, petrified, prone, restrained, stunned
Senses darkvision 30 ft., passive Perception 12
Challenge 4 (1,100 XP)

Special Traits

  • Feline Terror. Each creature in the swarm must succeed on a DC 12 Wisdom saving throw or fall prone and become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the swarm’s Feline Terror for the next 24 hours.
  • Keen Senses. The swarm has advantage on Wisdom (Perception) checks that rely on sight, hearing, or 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 cat. The swarm can’t regain hp or gain temporary hp.


  • Bites. Melee Weapon Attack: +6 to hit, reach 0 ft., up to two creatures in the swarm’s space. Hit: 14 (4d6) piercing damage, or 7 (2d6) piercing damage if the swarm has half of its hit points or fewer.


A Convergence of Felines. Seeing a group of cats (called a clowder) slinking down an alley barely registers in the minds of busy city-dwellers. Pests to some, pets to others, and invisible to most, the domestic housecat does not seem much of a threat. However, any beast with tooth and claw poses a threat on some level. And hundreds of those beasts, inspired and working together, can be a terrifying prospect.

The Cats and the Weather. The first sign a victim sees is cloudy, violent weather. The bluest, clearest daytime skies or the finest moonlit nights become stormy nightmares when the cats are on the prowl.

A Hissing, Seething Mass. Through the darkness provided by the suddenly darkened skies, the cats come together, some from their comfortable homes and others from their wild dens. The call spares no feline, and all types of cats join together to form the swarm. The victims often do not see the cats until it is too late. The only thing the victims notice is a single hiss that rises up from the mass of fur and death.

Section 15: Copyright Notice

Creature Codex. © 2018 Open Design LLC; Authors Wolfgang Baur, Dan Dillon, Richard Green, James Haeck, Chris Harris, Jeremy Hochhalter, James Introcaso, Chris Lockey, Shawn Merwin, and Jon Sawatsky.