Carapace, Silent (CR 1/8)

Tiny Aberration (Symbiont)
Alignment: Usually lawful evil
Initiative: +3 (Dex); Senses: blindsight 60 ft., darkvision 60 ft.,, Listen +2, and Spot +2

AC: 19 (+2 size, +3 Dex, +4 natural), touch 15, flat-footed 16
Hit Dice: 2d8+2 (11 hp)
Fort +1, Ref +3, Will +3
Speed: 5 ft.
Space: 2 1/2 ft./0 ft.
Base Attack +1; Grapple -6
Attack: -
Full Attack: -
Damage: -
Special Attacks/Actions: -
Abilities: Str 13, Dex 16, Con 13, Int 6, Wis 10, Cha 11 (Ego: 5)
Special Qualities: natural armor bonus, quiet, soul feeding, symbiont traits
Feats: Alertness
Skills: Listen +2, Move Silently +13, and Spot +2
Advancement: -
Climate/Terrain: Any underground
Organization: Solitary (symbiont)
Treasure/Possessions: -

Source: Dragon #308

Blindsight (Ex): A silent carapace is blind, but its entire body is a primitive sensory organ that can ascertain objects and creatures by scent and vibration within 60 feet. A silent carapace usually does not need to make Spot or Listen checks to notice creatures within range of its blindsight.

Quiet (Ex): A silent carapace can grant its host the benefit of the silent moves armor special ability. The host can activate this ability as a standard action; dismissing it is a free action. The effect lasts for 10 minutes or until dismissed. Each time this ability is activated, the host takes 1 point of Charisma damage.

Skills: A silent carapace gains a racial bonus on Move Silently checks.

Natural Armor Bonus (Ex): A carapace symbiont increases its host's natural armor bonus by +4.

Soul Feeding (Su): A carapace symbiont survives by consuming its host's personal essence. This ongoing process deals point of Charisma damage each day the carapace symbiont remains attached. Ordinarily, the host regains lost point of Charisma each night, just before the carapace symbiont drains a new point, keeping the host at an equilibrium point of -1 to its base Charisma. Some carapace symbionts have abilities that damage additional Charisma with each use (see individual descriptions).

A carapace symbiont has no way to attach itself to an unwilling host unless that host is helpless. In general, creatures seek out a carapace symbiont to gain its benefits and voluntarily attach it to their own bodies. On occasion, illithids apply carapace symbionts to helpless creatures to test the symbiont's powers or to enhance the combat abilities of slaves.

A silent carapace's outer padding of rubbery skin and fat helps its host move more quietly than otherwise would be possible.