A squirming and squeaky mass of rats with rotting flesh, torn and matted fur, and reddish blazing eyes moves toward you. Their semi-translucent skin shows discolored bones and muscle.
Shadow Rat Swarm CR 4
AC 15, touch 14, flat-footed 13 (+2 Dex, +1 natural, +2 size)
hp 39 (6d8+12)
Fort +4, Ref +6, Will +6
Defensive Abilities half damage from piercing and slashing, incorporeal form, shadow blend; Immune swarm traits, undead traits
Weaknesses swarm traits
Str 6, Dex 15, Con –, Int 2, Wis 12, Cha 14
Base Atk +4; CMB –; CMD —
Feats Improved Initiative, Lightning Reflexes, Skill Focus (Perception)
Skills Acrobatics +4, Climb +10, Perception +9, Stealth +19; Racial Modifiers +4 Stealth
A shadow rat swarm can, as a standard action, assume an incorporeal form for up to 1 hour per day. In this form, the swarm loses its natural AC bonus but gains a +2 deflection bonus to AC. While in this form, the shadow rat swarm is AC 16 (+2 deflection, +2 Dex, +2 size), touch 15, flat-footed 13. The shadow rat swarm can still swarm attack corporeal opponents while in its incorporeal form, but its attack only inflicts Strength damage and cannot distract foes or cause physical damage. The shadow rat swarm gains the incorporeal subtype while using this ability.
A shadow rat swarm deals Strength damage to living foes over which it swarms. A creature reduced to 0 Strength cannot move but does not die–at least, not until the swarm’s physical damage takes its toll.
Organization solitary, pack (2-4 swarms), or nest (5-8 swarms)
Shadow rats are essentially undead rats that can assume an incorporeal form. Other than their semi-translucent form, they resemble their earthly counterparts in all respects. A shadow rat swarm is simply a massive number of shadow rats that have cluttered or banded together for survival or food.
Shadow rat swarms can be found just about anywhere, but are most commonly encountered near graveyards, ruined temples, and haunted sewers.
Shadow Rat Swarm from the Tome of Horrors Complete, Copyright 2011, Necromancer Games, Inc., published and distributed by Frog God Games; Author Scott Greene.