Brain in a Jar (CR 4)
Alignment: Usually neutral evil
Initiative: +2 (Dex); Senses: blindsight 60 ft., darkvision 60 ft., Listen +9, and Spot +9
Languages: telepathy 100 ft.
AC: 13 (+2 Dex, +1 deflection), touch 13, flat-footed 11
Hit Dice: 3d12 (19 hp)
Fort +1, Ref +3, Will +6
Speed: Fly 30 ft.(good)
Space: 1 ft./-
Base Attack -; Grapple -
Special Attacks/Actions: Mind thrust, psionics, rebuke undead 6/day (+5, 2d6+6, 3rd)
Abilities: Str -, Dex 14, Con -, Int 16, Wis 12, Cha 16
Special Qualities: madness, undead traits, +4 turn resistance
Feats: Alertness; Iron Will
Skills: Bluff +9, Diplomacy +9, Knowledge (history) +9, Knowledge (psionics) +9, Knowledge (religion) +9, Listen +9, and Spot +9
Advancement: 4-9 HD (Tiny)
Mind Thrust (Su): A brain in a jar can spend a standard action to deliver a massive assault on the thought pathways of any one creature, undermining its intellect. This mind thrust deals 2d10 points of damage to any target creature that fails a DC 14 Will save. The save DC is Charisma-based.
Madness (Su): Anyone targeting a brain in a jar with a thought detection, mind control, or any sort of telepathic or psionic ability that makes direct contact with its tortured mind takes 1d4 points of Wisdom damage.
Psionics (Sp): 3/day- suggestion (DC 16), telekinesis (DC 18); 1/day - dominate person (DC 18). Manifester level 10th. The save DCs are Charisma-based.
Rebuke Undead (Su): A brain in a jar can rebuke or command undead as a cleric of the same level as the brain's HD
A brain in a jar prefers control to direct combat, since brains in fragile glass jars can't stand too much jostling. However, when it can't stay completely clear of combat, it seeks to put off aggressors with its mind thrust ability.
The brain in a jar is a masterpiece of preservation - but where alchemical preservatives leave off, necromancy picks up. An animate brain in a jar is, in truth, an undead creature. Additionally, possibly because it is free of the need to worry about controlling and animating an entire body, a brain in a jar possesses potent mental powers.
Of course, merely removing the brain of a zombie or some other undead creature and storing it in alchemical preservatives is not enough to create an undead brain with psionic ability. The ritual of extraction, the spells of formulation, and the alchemical recipes of preservation are closely guarded secrets held by only a few master necromancers.
The creation of a brain in a jar is difficult and fraught with danger, because once its mental powers are fully developed, this undead creature is adept at controlling the thoughts and minds of other creatures, especially living creatures. It is not unknown for a brain in a jar to take control over the necromancer who created it.
A brain in a jar weighs about 25 pounds, which includes the weight of the glass canister and the preservative fluids.