| Hit Dice: | 8d12 (52 hp) |
| Initiative: | +1 |
| Speed: | 15 ft. (3 squares), climb 15 ft. |
| Armor Class: | 13 (+2 size, +1 Dex), touch 13, flat-footed 12 |
| Base Attack/Grapple: | +4/— |
| Attack: | Swarm (1d6 plus disease) |
| Full Attack: | Swarm (1d6 plus disease) |
| Space/Reach: | 10 ft./0 ft. |
| Special Attacks: | Disease, distraction |
| Special Qualities: | Damage reduction 5/slashing, darkvision 60 ft., swarm traits, undead traits |
| Saves: | Fort +2, Ref +3, Will +6 |
| Abilities: | Str 4, Dex 13, Con —, Int —, Wis 10, Cha 1 |
| Skills: | — |
| Feats: | — |
| Environment: | Any |
| Organization: | Solitary, pack (2–4 swarms), or infestation (7–12 swarms) |
| Challenge Rating: | 4 |
| Treasure: | None |
| Alignment: | Always neutral evil |
| Advancement: | — ♊ |
| Level Adjustment: | — |
Leaving a stinking trail of blood and rotting entrails, the horde of tiny rat corpses squirms and squeals toward its victims.
Like a bone rat swarm, a corpse rat swarm is made up of countless undead rats. These, however, are closer to zombies than skeletons, with hunks of rotting flesh still hanging on their bones. They are even more disease-ridden than a normal rat swarm, and every bit as hungry for flesh.
A corpse rat swarm seeks to engulf and devour any living prey it encounters. A corpse rat swarm deals 1d6 points of damage to any creature whose space it occupies at the end of its move.
Disease (Ex): Filth fever—swarm attack, Fortitude DC 16, incubation period 1d3 days, damage 1d3 Dex and 1d3 Con. The save DC is Constitution-based and includes a +2 racial bonus.
Distraction (Ex): Any living creature that begins its turn with a corpse rat swarm in its space must succeed on a DC 15 Fortitude save or be nauseated for 1 round. The save DC is Constitution-based.
Turning: See Undead Swarms and Turning.
Source: Libris Mortis, page 92. Added the reference to turning undead swarms.