Originally from the Far Realm, Mind Flayers; also called "Illithids" or "Brain-Eaters," are evil and sadistic beings who dwell in the Underdark of Corwyn.


Illithids are humanoid in appearance, but with octopus-like heads sprouting four long tentacles. Their skin is pale mauve in color, and glistens with slime. The creatures usually measure six feet in height, but appear as thin and frail.


Due to their powerful mental-domination abilities, Illithids are almost universally feared. They are also loathed because of their diet; which consists of feeding upon the brains of other sentient creatures. A gruesome appetite which constantly requires new victims.

When encountered, Mind-flayers are usually accompanied by two or more Grimlock thralls, who are mentally bound to their individual master.

Illithids are capable of speaking telepathically and it is their preferred communication method. Although Illithids will cooperate or negotiate with other creatures to achieve a common goal, they will back away without warning at the first sign that something is no longer to their advantage.

Because of their natural psionic abilities, Beholders, Drow, Duergar, and the other intelligent Underdark races give great deference to these creatures.


Illithids are hermaphroditic creatures who, once in their lifetime, spawn a mass of larvae through a clutch of eggs. This birthing is done in a process whereby the Illithid lays the eggs while partially submerged in the brain pool. After a few weeks, the eggs hatch.

Once hatched, these larvae resemble miniature four-tentacled tadpoles, which are left to develop in the pool of the nearest elder brain for several years. The vast majority of the tadpoles die in the pool and are digested by the elder brain.

After many years, the surviving larvae mature. They are then are inserted into the brains of captive sentient creatures.

Hosts are determined in a very specific manner. All specimens must be intelligent, humanoid creatures between 5 feet 4 inches and 6 feet 2 inches tall.

The most desirable of races for hosts are Githzerai or Githyanki, but because of current political realities, the Illithid society has long been forced to settle for Humans, Elves, or Grimlocks.

Upon being implanted, a larva quickly grows and consumes the host’s brain. Eventually a cocooning process occurs, in which the the host’s physical form is absorbed entirely. After several years, a sentient, young Illithid emerges from the cocoon. This process is called "Ceremorphosis."


All Illithids possess formidable mental prowess, with an array of mind-affecting spells to take control of prey, as well as a powerful mind blast ability which can affect whole groups of foes.

The mind flayer's mind blast is a 60-foot (20-m) cone that will stun anyone caught within it. All Illithids can also cast three mind-affecting spells at-will: charm monster, detect thoughts, and suggestion. Mind flayers are also capable of using levitate and plane shift.

Mind Flayer Diet


Normally, a mind flayer will use its mind blast ability to stun a foe and then drag it away to feed. Once it has captured its intended victim, the Illithid attaches all four of its tentacles to the head of its victim. It then sucks out the victim's brain, resulting in instant death.

Mind flayers normally use their mental-domination abilities to enslave other creatures. The Illithids call these minions "Thralls," and the subjugated creatures remain under their total control until their death. In the event of war, Illithids have frequently used their mind-control abilities extremely effectively upon the battlefield.


In addition to telepathic communication, the Mind-Flayers also use "Qualith," their own unique, written language. This strange language takes the form of multiple parallel, textured lines. This incomprehensible lines actually convey meaning when an Illithid scans them, using its four tentacles.

The script is imprinted psionically onto the surface and transmitted to the reader via the thoughts of the Mind-Flayer who inscribed it. It can be written on parchment, in books, or carved into surfaces. Degradation of the material can cause the message to fade over time.

Because of its psionic component, Qualith is impossible for non-Illithids to read, unless a magical "comprehend languages" spell is used.


Mind-Flayer communities are small, ranging in size from two hundred to two thousand. These totals include both Illithids and their thralls. Each mind flayer in a community likely has at least two personal thralls to do its bidding, plus many additional community slaves for use as guards and custodians.

In most Illithid communities, the slave population far outnumbers that of the Mind Flayers. For example, the large Illithid city of Sharularen has a total population of 36,000; but mind flayers only account for about 4,500 of that number.

When problems arise or the Mind-Flayers wish to discover some secret, they will formed an "Inquisition." These inquisitions were made up of a team of illithids, not unlike an adventuring party.

Each Illithid will use their own talents and abilities to achieve the inquisition's goal. If a situation becomes too difficult for a team of Inquisitors to handle, the illithid community will marshal its forces and put together a "Cult." A cult is much larger than an inquisition and is usually spearheaded by a Ulitharid; a Mind-Flayer noble.

Although Mind-Flayers willingly work together to achieve a common goal, they are constantly attempting to gain more control within their community. But all Illithid efforts are related to a single desire; to curry favor with the "Elder Brain."

The elder brain is the heart of the Illithid community. Held in a large pool of briny fluid, the elder brain consists of all the brains of the dead Mind-Flayers in the community, and is an almost sacred source of information and history for the creatures.


Mind-flayer society is divided into segments, each with a specialized purpose. Some of the more well-known Creeds include:

  • the Arbiters: this group resolves disputes
  • the Artificers: this group create new technology and inventions
  • the Conservators: this group oversees the birthing and maturity process, also education
  • the Inquisitors: this group serves as spies and intelligence-gatherers
  • the Militant: this group serves as the community defense force
  • the Venerators: this group serves as the equivalent of a priesthood, specializing in religious and spiritual matters.


During Ceremorphosis, some Illithids emerge from process bigger, stronger, and more psionically powerful than a regular Mind-Flayer. These creatures are called "Ulitharids" or "Illithid-nobles." These creatures are taller, stronger, and more intellectually powerful. Visually, they are distinguishable by having six tentacles instead of the regular four.

A Urophion is a subspecies of mind flayer created as guardians for a mind flayer community. An urophion is created by using a roper that has survived the tadpole implantation process. These creatures are usually treated as second-class citizens but are permitted to join with the elder brain upon death.



Mind flayer religion was once non-existent, and the mind flayers were strictly atheistic. But legend has it, that all changed in the Second Age.

After the Illithids had conquered the Dwarven realm of Tor-Kazon, they captured many dwarves and brought them back to their city of Sharularen.

Their original plan was to create "Duergar;" a superior slave-race of dwarves; highly skilled in warfare, engineering, and psionics. These slave-dwarves would be unwaveringly loyal to the Illithid race. However, when the experimentation was occurring, the dwarf-slaves began to stage uprisings and rebellions inside the city of Sharularen.

According to myth, the rebellion plunged the Illithid city into chaos. The only reason the city did not fall to the Duergar rebellions was because of the sudden appearance of the Mind-Flayer Deity; Manzecorian.

Since Manzecorian's appearance, many Illithids have become deeply religious, and developed even more formidable psionic powers. After this point, whole sects of Mind-Flayers became fanatical priests to this strange Deity from Charos.


Mind Flayers are originally from Charos; the Realm of Madness, where for thousands of years they had an enormous empire on their world, called Zarum.

That empire collapsed long ago, and many Illithids fled to the World of Oris; hiding in deep underground caverns throughout the Underdark. Today, they are still hunted by roving War-bands of both Githyanki and Githzerai.

The Great Illithid Empire on Charos

Eons ago, the Illithids founded Zarum; a huge empire. which for thousands of years, controlled much of Charos. That empire was destroyed long ago in an uprising.

The Illithid City of Nhak-Vorad


Population: 1 Elder Brain, 230 Illithids, 2,000 slaves/thralls

1st level: Entrance cavern; a large half-mile diameter cavern with 200-ft high ceilings. In the center is a small square stone fortress with four guard towers, and a 20 foot wall. Inside are about three-dozen small huts and a central stone dome structure.

The huts hold about 300 grimlocks, and the dome holds 4 Illithid overseers. In the center of the dome a securely locked chamber that contains the entrance spiral stair going done vertically 100 feet to the next level.

Security is provided by 100 ordinary grimlocks manning the gate, walls, and towers, as well as 20 Grells who fly about the cavern edges and patrol its perimeter.

2nd level: Guard level. This level contains the entry foyer, surrounded by 20 Grimlock elite troops and 4 Illithids. Connected nearby is the main Grimlock barracks where an addition 40 Elite Grimlocks sleep. (1/3 are always on duty) Past it is the Gate to the city itself, which leads down a long passage to the main cavern below.

3rd level. The main cavern. This cavern is the city center. It contains 200-250 chambers cut into the walls of the cavern, which are the living quarters for the Illithid residents. These chambers are accessible only by levitate or flying ability. The main floor contains several areas:

1. The main pool
2. The arena
3. The laboratory complex
4. The tamer facility
5. The feeding pens
6. The temple to Ilsenene
7. the grand bazaar
8. the gates to the final level

4th level: the elder Brain is located here in a central circular chamber, there are birthing chambers allocated nearby for Illithid birth pods. There are also chambers for the attendants, senior Illithids who supervise the birthing process and attend the Elder Brain.

All important conference with the ruling Illithid council called the Elder Concord are held in this chamber. In four alcoves around the Elder Brain chamber are four large Brain Golems


Illithids commonly use the following creatures: