Balhannoth (CR 10)

Large Aberration
Alignment: Usually chaotic neutral
Initiative: +7(+3 Dex, +4 Improved Initiative); Senses: blind, dweomersight 120 ft., and Listen +6
Languages: -

AC: 21 (-1 size, +3 Dex, +9 natural), touch 12, flat-footed 18
Hit Dice: 14d8+84 (147 hp); DR: 15/magic
Fort +10, Ref +8, Will +12
Speed: 50 ft. and Climb 50 ft.
Space: 10 ft.; Reach 10 ft. (15 ft. with tentacles)
Base Attack +10; Grapple +23
Attack: Melee: 2 slams +18 each (2d6+9/19-20) and bite +13 (1d8+4)
Special Attacks/Actions: antimagic grapple
Attack Options: Power Attack, constrict +1d8, improved grab, magic strike
Abilities: Str 28, Dex 17, Con 23, Int 3, Wis 12, Cha 8
Special Abilities: Aura: dimensional lock; Immune: gaze attacks, illusions, visual effects; SR 18
Special Qualities: Camouflage
Feats: Improved Critical (slam), Improved Initiative, Iron Will, Lightning Reflexes, Power Attack,
Skills: Climb +17, Hide +16, Jump +17, Listen +6, and Move Silently +13
Advancement: 15-20 HD (Large); 21-30 HD (Huge)
Climate/Terrain: Any underground
Organization: None
Treasure/Possessions: Standard (1/2 standard amt of coin, double items)

Source: Monster Manual IV

Dweomersight (Su) A balhannoth can sense the presence and position of magic auras within 120 feet of itself, and knows the strength and school of each one. It can pinpoint the location of any creature with ongoing spells cast on it, carrying magic items, or otherwise using magic, and it can notice anything within the area of a magic effect (including its own dimensional lock aura). This otherwise functions like blindsense.

Dimensional Lock (Su): As the Dimensional Lock spell, 20-foot radius centered on the balhannoth, CL 10th. This effect moves with the creature.

Constrict (Ex): A balhannoth deals 1d8 points of damage with a successful grapple check, in addition to damage from its slam attack.

Improved Grab (Ex): To use this ability, a balhannoth must hit an opponent of up to Large size with a slam attack. It can then attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple check, it establishes a hold and can constrict.

Antimagic Grapple (Su): When a balhannoth grapples an opponent, all the magical properties of that opponent's magic items are suppressed. In addition, a creature grappled by a balhannoth cannot cast spells or use spell-like or supernatural abilities. A balhannoth automatically suppresses magic items by holding or wearing them.

Camouflage (Ex): A balhannoth's skin changes color to match its surroundings. As a result, a balhannoth can use the Hide skill in any sort of natural terrain.

Skills: A balhannoth has a +15 racial bonus on Hide checks due to its camouflage ability. It has a +8 racial bonus on Climb checks and can always choose to take 10 on Climb checks, even if rushed or threatened.

Horrid aberrations of the subterranean realm, balhannoths hunt by tracking magical energy. They can "see" magic but are otherwise blind. Nothing magical functions in their powerful grips, making these predators especially deadly to those who rely on spells or magic items.