Spell Weaver (CR 10)

Medium Monstrous Humanoid
Alignment: Usually neutral
Initiative: +3 (Dex); Senses: darkvision 60 ft., Listen +16, and Spot +16

AC: 18 (+3 Dex, +5 natural), touch 13, flat-footed 15
Hit Dice: 10d8-10 (36 hp); DR: 15/special (see text)
Fort +2, Ref +10, Will +10
Speed: 30 ft.
Space: 5 ft./5 ft.
Base Attack +10; Grapple +9
Attack: 2 slams +9
Full Attack: 2 slams +9
Damage: Slam 1d3-1
Special Attacks/Actions: Spell-like abilities, spells
Abilities: Str 9, Dex 16, Con 9, Int 18, Wis 17, Cha 16
Special Qualities: Adaptive energy resistance, reactive skin
Feats: Empower Spell; Enlarge Spell; Extend Spell; Heighten Spell; Spell Focus (Abjuration); Spell Focus (Evocation); Spell Penetration
Skills: Knowledge (arcana) +17, Knowledge (the planes) +17, Listen +16, Spellcraft +19, Spot +16, and Use Magic Device +16
Advancement: 11-30 HD (Medium-size)
Climate/Terrain: Any land
Organization: Solitary or raid (3-6)
Treasure/Possessions: Double items (magic items only)

Source: Monster Manual II

Spell-Like Abilities: Always active - see invisibility: at will - detect magic, invisibility; 1/day - plane shift. Caster level equals spell weaver's effective sorcerer level; save DC 13 + spell level.

Spells: A spell weaver casts spells as a sorcerer two levels higher than its Hit Dice. (That is, a spell weaver with 10 Hit Dice casts spells as a 12th-level sorcerer; spells known 9/5/5/4/3/2/1; spells/day 6/7/7/7/6/5/3; save DC 13 + spell level, or 15 + spell level for Abjuration and Evocation spells.) A spell weaver prefers combinations of spells that focus on attacks, defense, and transportation.

Chromatic Disk: A spell weaver is never without its chromatic disk. This 6-inch-diameter indestructible disk glows with colors that slowly shift through the spectrum. This object stores ten additional spell levels of energy that the creature can tap and use as it wishes - the spell weaver could, for example, cast two extra 5th-level spells in a day, or three 3rd-level spells and one 1st-level spell, or any other combination of extra spell levels that adds up to ten, so long as no single spell is higher than 5th level. (For this purpose, two 0-level spells are equivalent to one 1st-level spell.) To tap this spell energy, a spell weaver must hold the chromatic disk in at least one of its hands. The disk automatically recharges itself to full power every night, at midnight. A spell powered by the disk is cast as though the caster had the Spell Focus feat for the spell in question.

Only a spell weaver can utilize a chromatic disk. Should any other creature pick one up and try to tap its energy (by employing the Use Magic Device skill, for instance), it explodes, dealing 4d10 points of damage to everything within a 30-foot radius.

Immunity to Mind-Affecting Effects: Because its alien mind functions differently than those of other creatures, a spell weaver is immune to all mind-affecting spells and effects.

Shielded Mind (Ex): A tempts by creatures of other races to communicate telepathically with a spell weaver, or to read its mind, always fail. A creature making such an attempt must succeed at a Will save (DC 17) or be affected as if by a confusion spell (caster level equals spell weaver's effective sorcerer level) for 1d6 days. This effect can be dispelled or removed with a heal effect.

Spell Weaving (Ex): These monsters are infamous for their ability to cast more than one spell at a time. Casting a spell occupies a number of the spell weaver's arms equal to the spell's level (maximum 6th). A spell weaver can cast more than one spell simultaneously, as long as the sum of the spell levels is six or less. It could, for example, cast one 6th-level spell, one 4th-level and one 2nd- level spell, one 3rd-level and three 1st-level spells, six 1st- level spells, or any combination of spells whose levels add up to six or less. (A single 0-level spell occupies one arm.)

Telepathy (Su): Spell weavers can communicate with each other telepathically at a range of up to 1,000 miles.

A spell weaver is pathetically weak in melee but powerful in magic. Its ability to cast multiple spells simultaneously makes it a dangerous opponent indeed. A spell weaver usually remains invisible until it is ready to attack, then uses plane shift to escape, hopefully in possession of the magic for which it came.