Skulking Cyst (CR 4)

Small Undead
Alignment: Always chaotic evil
Initiative: +4 (Dex); Senses: blindsight 60 ft., darkvision 60 ft., Listen +11, and Spot +11
Languages: Common, does not speak

AC: 19 (+1 size, +4 Dex, +4 natural), touch 15, flat-footed 15
Hit Dice: 4d12 (26 hp)
Fort +1, Ref +5, Will +6
Speed: 30 ft., climb 30 ft., swim 30 ft.
Space: 5 ft./5 ft.
Base Attack +2; Grapple -2
Attack: Intestine loop +6 melee
Full Attack: 2 intestine loops +6 melee
Damage: Intestine loop 1d4 plus attachment
Special Attacks/Actions: Attach, blood drain, spell-like abilities
Abilities: Str 10, Dex 19, Con -, Int 13, Wis 14, Cha 16
Special Qualities: inescapable craving, resistance to fire 5, undead traits, +2 turn resistance
Feats: Alertness; Weapon Finesse
Skills: Climb +15, Hide +23, Listen +11, Move Silently +19, Search +8, Spot +11, and Tumble +7
Advancement: -
Climate/Terrain: Any
Organization: Solitary or concentration (3-9)
Treasure: Standard

Source: Libris Mortis

The horrible creature walking into view is a mass of free-roaming intestines, flaccid organs, and a few odd rib bones. Dragging behind it like a dead weight is a lolling, maggot-ridden humanoid head.

A skulking cyst is disgorged from the rotting corpse of a living creature, born of a necrotic cyst that eventually kills its host (see the necrotic cyst spell,).

A skulking cyst prefers shadows and dark corners, only revealing the horror of its form when it strikes lone victims from hiding. Though often cloaked in the detritus of a previous victim, the skulking cyst's true "heart" is a 1-foot-diameter spherical sac that contains fluid and semisolid necrotic flesh, which slowly undulates as if in a mockery of breath.

A skulking cyst does not speak, but it understands Common and the languages its fleshy carapace originally spoke in life.