CR 5 (1600 XP)
Always N Medium aberration
Init +3; Senses all-around vision, darkvision 60 ft.; Perception +12
AC 19, touch 13, flat-footed 16 (+3 Dex, +6 natural)
hp 46 (4d8+28)
Fort +8, Ref +4, Will +5
Defensive Abilities amorphous
Immune critical hits, precision damage
Speed 10 ft., swim 20 ft.
Melee 6 bites +7 (1d4 plus grab)
Special Attacks blood drain, engulf (6d4 damage plus 2 Con damage, AC 13, hp 4), gibbering, ground manipulation, spittle (+6 ranged touch)
Str 10, Dex 17, Con 24, Int 4, Wis 13, Cha 12
Feats Weapon Finesse, Weapon Focus (bite)
Skills Perception +12, Swim +8; Racial Modifiers +4 Perception
Skill Points 4
Languages Random fragments of innumerous languages
Environment any underground
Treasure standard (indigestibles)
All-Around Vision (Ex): A gibbering mouther sees in all directions at once. It cannot be flanked.
Amorphous (Ex): A gibbering mouther's body is malleable and shapeless. It is immune to precision damage (like sneak attacks) and critical hits, and can move through an area as small as one-quarter its space without squeezing or one-eighth its space when squeezing.
Blood Drain (Ex): On a successful grapple check after grabbing, several of the creature's mouths attach to its target. Each round it maintains its grapple, its mouths automatically deal 1d4 points of bite damage and 1 point of Constitution damage as it drains its victim's blood.
Engulf (Ex): This ability functions as swallow whole, except for the following changes. An engulfed creature is trapped in the gibbering mouther's body, where several of its mouths continue to feed and drain blood. A gibbering mouther can engulf only one foe of its size or smaller at a time. If an engulfed creature cuts its way free (the mouther's damage reduction still applies to those inside), the mouther simply flows together again and can still use its engulf attack.
Gibbering (Su): As a free action, a gibbering mouther can emit a cacophony of maddening sound. All creatures other than gibbering mouthers within 60 feet must succeed on a DC 13 Will save or be confused for 1 round. This is a mind-affecting compulsion insanity effect. A creature that saves cannot be affected by the same mouther's gibbering for 24 hours. The save DC is Constitution-based.
Ground Manipulation (Su): At will as a standard action, a gibbering mouther can cause stone and earth under its body to grow soft and muddy. The ground remains muddy for 1 minute after the mouther moves off of the location. A gibbering mouther can move through these areas with ease, but other creatures treat them as difficult terrain.
Spittle (Ex): Each round as a free action, a gibbering mouther can emit a stream of acidic spittle at one target within 30 feet. On a successful attack, the target is blinded for 1d4 rounds unless he succeeds on a DC 18 Fortitude save. The save DC is Constitution-based.