Brain in a jar

A brain in a jar was the brain of a creature preserved and animated through alchemy and undeath. Liberated of its body, it was capable of great and disturbing psionic powers.

Creation
A masterwork of the art of preservation of biological matter, a brain in a jar was the product of both alchemy and necromancy, maintaining life in a state of undeath. It was not sufficient to pluck the brain of a zombie or other undead and put it in preservatives, as it would still lack thought and psionic power. Instead, creation of a true brain in a jar required a specific extraction ritual, spells of formulation, and recipes of alchemical preservation, all of which were well-kept secrets known to a select few master necromancers.

Whatever the process, it was difficult and hazardous for, as its powers grew, the brain in a jar was apt to dominate the mind of the necromancer foolish enough to create it.

Description
As the name said, it was a disembodied brain floating within a glass canister filled with alchemical preservative fluids (such as embalming fluid ). The brain was shrunken and wrinkled in undeath, and the jar grew grimy with time. In all, brain, jar, and fluid typically weighed around.

Abilities
At will, a brain in a jar could launch a mind thrust, which inflicted an intense psychic assault on the mental pathways of a target creature, undermining its intellect and doing physical harm if they lacked the will to resist.

Thrice a day each, it could make a suggestion that would influence a victim's behavior and move objects and creatures with the power of telekinesis. It could also mentally dominate a person once a day. It could communicate via telepathy with any being capable of language in. Being undead, it could also command and rebuke other undead in the same manner as a cleric, but it was resistant to being turned itself.

Using any telepathic or psionic power to sense or read the thoughts or control the mind of a brain in a jar, or make any other kind of direct mental contact with it, would cause the one making the attempt to experience its madness and suffer mental damage.

Not immobile, the brain in a jar was capable of flight, as fast as a humanoid could walk, with good maneuverability.

Combat
Being rather fragile, brains in jars were understandably unwilling to get into battle and would try to fly to safety. They would rather control than combat creatures. But when they couldn't avoid a fight, they struck at attackers with their mind thrust power.

Personality
No longer obliged to control an entire body, the brain in a jar acquired great powers of the mind. Instead, it controlled the minds and bodies of other beings, particularly the living. But it was also tortured and insane, and often twisted toward evil.

History
After the star elves of Sildëyuir executed the corrupt wizard Mourel Duskwalker, his apprentice Kyjal Stardancer retrieved his head. Mourel had been experimenting with a certain method and Kyjal used it to extract his master's brain, which he placed in a jar of embalming fluid. Then, using another of Mourel's techniques, Kyjal animated the brain. For defense and mobility, Mourel had a compartment cut into the chest of a commanded girallon zombie that could carry his jar. Over a century as a brain in a jar, Mourel evolved into a greater kind of undead, but he, Kyjal, and their minions remained trapped in the citadel of Tir'in'tiral sealed away in the Night Realm.

Notable Brains in Jars

 * Mourel Duskwalker

Background
While a common concept in science fiction and horror, the brain in a jar in D&D may be based on the Living Brain of Rudolph Von Aubrecker created by Victor Mordenheim in the Ravenloft setting.

Appearances

 * Adventures
 * The Twilight Tomb • Icewind Dale: Rime of the Frostmaiden
 * Organized Play & Licensed Adventures
 * Lost Laboratory of Kwalish • Stardock Under Siege