Cerebrilith

A cerebrilith was a type of tanar'ri demon native to the Abyss. It was notable for possessing psionic powers.

Physical description
A cerebrilith appeared as a giant ogre-like humanoid creature, standing around 8 feet (2.4 meters) high when upright in battle. However, it normally knuckle-walked on all fours due to its hunched back. The body was relatively gangly, with skin turned slick and slimy as if it continually leaked some fluid. Its skull was bulging and elongated, sweeping back and merging into its hunched back, with a bony brow and protruding fanged jaw with long, thin tongue. Its most obvious feature was a hideously swollen and exposed brain, shielded beneath a lattice of its spinal bones.

Behavior
Cerebriliths spent their time cultivating their mental powers, usually acting alone or in groups of up to four, by hunting and killing mortal prey. They loved to kill intelligent beings and extract their brains, which they would examine in an effort to gain fresh insights into the powers of the mind.

They only joined demon armies in specialist roles to meet specific purposes, such as to a slay a mortal psionicist or psionic creature.

They could also use their powers of mental domination in larger schemes.

History
In the Year of Rogue Dragons, 1373 DR, the Zhentarim of the Citadel of the Raven summoned a cerebrilith to control and dominate the emerald dragon Vercevoran, who was kept captive in a castle at Hulburg on the Moonsea. The cerebrilith remained disguised beneath a great cloak and hood. On the 2nd of Mirtul, Pavel Shemov and Will Turnstone came to rescue Vercevoran, but were surprised by the cerebrilith, who commanded the dragon to attack them. As Will lured Vercevoran away, Pavel battled and finally slew the cerebrilith.

Combat
These psionic demons opened battle with an assault of telepathic powers. When in melee range, they fought with teeth and claws with psionically enhanced force.

Powers
Cerebriliths possessed all the standard magical powers of a tanar'ri demon, and complemented these with an array of psionic powers of the telepathy discipline, causing mental damage, mind-reading and domination. It could communicate via telepathy.

A cerebrilith could summon another of its kind or a number of dretches.