This spherical mass of flesh is covered in hundreds of mouths and eyes. Its floating, churning bulk pulses like a beating heart.
AC 33, touch 17, flat-footed 24 (+9 Dex, +16 natural, –2 size)
Speed 10 ft., burrow 20 ft., fly 20 ft. (good), earth glide
Str 28, Dex 29, Con 23, Int 20, Wis 24, Cha 20
Environment any underground
Eye Rays (Su) As a free action, a gibbering orb can emit colorful beams from its eyes. Collectively, these eye rays duplicate the effects of a prismatic spray spell (CL 20th, DC 28). The gibbering orb must succeed on a ray attack (ranged touch +30) against each creature in the area of this effect or that creature is unaffected. The save DC is Charisma-based.
Gibbering (Su) As a free action, a gibbering orb can emit a cacophony of maddening sound. All creatures within 60 feet that hear this gibbering must succeed on a DC 28 Will save or be permanently confused, as if affected by an insanity spell. This is a sonic mind-affecting compulsion insanity effect. A creature that saves cannot be affected by the same orb's gibbering for 24 hours. The save DC is Charisma-based.
Ground Manipulation (Su) At will as a standard action, a dark heart of the earth can cause terrain made of stone and earth to grow soft and muddy. This affects all such terrain within a 120-foot radius for a duration of 1 minute. A gibbering orb or gibbering mouther can move through these areas with ease, but other creatures treat them as difficult terrain.
Hostile Blood (Su) As an immediate action, whenever a dark heart of the earth is hit with a piercing or slashing weapon, the dark heart may choose to shed blood that transforms into a gibbering mouther. Doing so deals 46 points of untyped damage to the dark heart of the earth and causes a gibbering mouther appears in anywhere within the dark heart's space. (The gibbering mouther falls if it doesn't appear on a surface that can support its weight.)
Vulnerable to Sunlight (Ex) If a dark heart of the earth enters an area of direct sunlight, it is staggered for 1 round. If the dark heart of the earth remains in direct sunlight at the end of that duration, it dies and its remains crumble to dust.