Spellgaunt (CR 12)

Large Magical Beast
Alignment: Always neutral
Initiative: +2 (Dex); Senses: darkvision 60 ft., low-light vision, and Spot +26

AC: 18 (-1 size, +2 Dex, +7 natural), touch 11, flat-footed 16
Hit Dice: 16d10+48 (136 hp); DR: 15/magic, cold iron
Fort +13, Ref +12, Will +5
Speed: 40 ft., climb 20 ft.
Space: 10 ft./5 ft.
Base Attack +16; Grapple +15
Attack: Bite +24 melee and 2 claws +17 melee
Full Attack: Bite +24 melee and 2 claws +17 melee
Damage: Bite 1d8+8, claw 1d6+2
Special Attacks/Actions: Disjunctive bite, enhanced bite, force web, snatch item
Abilities: Str 18, Dex 14, Con 16, Int 13, Wis 11, Cha 21
Special Qualities: detect magic, quick leap, SR 35
Feats: Combat Expertise; Dodge; Improved Disarm; Improved Trip; Multiattack; Weapon Focus (bite)
Skills: Balance +16, Climb +12, Hide +19, Jump +28, and Spot +26
Advancement: 17-30 HD (Large); 31-45 HD (Huge)
Climate/Terrain: Any forest, mountains or underground
Organization: Solitary, pair, or nest (10-40)
Treasure/Possessions: None

Source: Monster Manual II

Disjunctive Bite (Su): A magic item bitten by a spellgaunt (see Attacking an Object in Chapter 8 of the Player's Handbook), must make a successful (DC 23) or instantly become a non-magical object. A spellgaunt feeding on an artifact has a 33% chance of destroying the item. If it destroys the item it must make a successful save (DC 25) or die instantly from an overwhelming ingestion of magical energy.

A spellcaster or a creature with supernatural or spell-like abilities that is bitten by a spellgaunt must make a Fortitude save (DC 23) or lose the ability to cast spells or use its magical abilities for 1d2 rounds.

Enhanced Bite (Ex): A spellgaunt's fangs function as +4 weapons.

Force Web (Su): A spellgaunt can spray flexible strands of sticky, invisible force at a single Medium-size or smaller target up to 20 feet away. A successful Reflex save (DC 23) lets target avoid the webs; failure means the creature is stuck and entangled (-2 penalty on attack rolls and -4 penalty to Dexterity). A force web is immune to damage from most spells, including dispel magic. However, disintegrate immediately destroys a force web, and it is also vulnerable to the effects of a sphere of annihilation or a rod of cancellation. Since force webs extend into the Ethereal Plane, they also affect ethereal creatures. A force web dissolves after 1d4 hours.

Snatch Item (Ex): A spellgaunt can take an openly displayed magic item away from an opponent with a successful disarm attempt, whether or not the item is actually a weapon. It cannot remove armor items that are attached at multiple locations, but it can snatch forcefully enough to break a single strap or other such attachment - the strap holding a wand to an opponent's belt, for example.

Detect Magic (Su): A spellgaunt can see magical auras in its line of sight to a range of 120 feet. It immediately senses the aura strength of each magic item and magical effect it detects.

Quick Leap (Ex): A spellgaunt make a standing jump as a free action.

Skills: A spellgaunt receives a +4 racial bonus on Hide checks, +6 racial bonus on Jump checks, and a +12 racial bonus on Spot checks.

A spellgaunt senses magic items and attacks any creature that carries one. It usually tries to immobilize foes with its force web first, then moves in to feed, drinking up the strongest magic first. Foes that evade its webs are bitten and clawed. If outnumbered, a spellgaunt moves quickly to snatch any visibly displayed magic items, then flees to its lair to feed in peace.