Homebrew Illithid Species Details

Illithids, also known as Mind Flayers, are evil and sadistic aberrations, feared by sentient creatures on many worlds across the multiverse due to their powerful innate psionic abilities. Dwellers of deep Underdark areas, these alien humanoid-looking beings seek to expand their dominion over all other creatures, controlling their minds to use them as hopeless slaves and devouring their brains for sustenance. Their natural psionic abilities also make mind flayers respected in the eyes of the drow, beholders, duergar, and the other dominant races of the Underdark

Tyrants, Slavers and Planar Voyagers

Mind flayers are tyrants, slavers, and planar voyagers. They view themselves as masterminds, controlling, harvesting, and twisting the potential of other creatures to further their evil and far-reaching goals. Although they cooperate to achieve a goal, they back away at the first sign that something was not profitable to their self-serving interests. Mind flayers are aggressive and elitist and will attempt to mentally dominate any non-slave, non-illithid they meet. However, despite their aggressiveness, illithids are ultimately a paranoid and fearful race. They are relentlessly hunted by the gith, so any mind flayer colony's first priority was concealment and survival. Emotionally, a mind flayer appears detached and calm, showing no signs of passion or loss of control. However, sometimes they show great bouts of anger, which are difficult to identify as true emotions or mere display. The mind flayer mind knows only negative emotions, only finding fulfilment in the angry and sadistic act of consuming a brain. The closest to happiness any mind flayer could know was in its pride and in satisfying its curiosity.

Alien Horrors

---

Mind flayers were humanoid in appearance, but with an octopus-like head with four tentacles surrounding a lamprey-like mouth. They are warm-blooded amphibians whose blood has a silvery-white colour. Mind flayers healthy from brain-rich diets excreted a kind of slimy mucous substance that coated their mauve skins. Their hands had long reddish fingers and lack the index finger and their feet were webbed. Mind flayer eyes are extremely sensitive to bright light and considered it painful, a characteristic that some githyanki scholars attributed to the fact that their alien anatomy focuses light in a strange way. Their vision is also more sensitive to the recognition of geometric patterns than that of other humanoids.

Pisonic Commanders 

Mind flayers possess psionic powers that enable them to control the minds of creatures such as troglodytes, grimlocks, quaggoths, and ogres. Illithids prefer to communicate via telepathy and use their telepathy when issuing commands to their thralls.

When an illithid meets strong resistance, it avoids initial combat as it orders its thralls to attack. Like physical extensions of the illithid’s thoughts, these thralls interpose themselves between the mind flayer and its foes, sacrificing their lives so that their master can escape.

Hive Mind Colonies

Solitary mind flayers are likely rogues and outcasts. Most illithids belong to a colony of sibling mind flayers devoted to an elder brain — a massive brain-like being that resides in a briny pool near the center of a mind flayer community. From its pool, an elder brain telepathically dictates its desires to each individual mind flayer within 5 miles of it, for it is able to hold multiple mental conversations at once.

Hunger of the Mind

Illithids subsist on the brains of humanoids. The brains provide enzymes, hormones, and psychic energy necessary for their survival. An illithid healthy from a brain-rich diet secretes a thin glaze of mucus that coats its mauve skin.

An illithid experiences euphoria as it devours the brain of a humanoid, along with its memories, personality, and innermost fears. Mind flayers will sometimes harvest a brain rather than devour it, using it as part of some alien experiment or transforming it into an intellect devourer.

Illithid Traits

Mind flayers have innate Psionic abilities and have a physiology designed to help them extract and feast upon the brains of intelligent creatures

Telepathy

Illithids are capable of speaking Undercommon and Deep Speech but prefer telepathic communication.

They also have a form of written language called Qualith, which consists of patterns of four lines imbued with psionic energy, capable of conveying not only text but also the author's thoughts. Without the use of magic, it can only be read by other illithids.

Mind Blast

Illithids have the special ability to stun their opponents. You can force anyone creature within 30 feet of you to make an Intelligence saving throw. If they fail, they are stunned and must remake the saving throw at the end of their turn. You can only have one creature Stunned in this way at a time, and this ability uses Concentration. When they succeed on the saving throw, they are not stunned, and you cannot use this ability again until you finish a short or long rest. The Save DC for this ability is 8 + Proficiency Bonus + Intelligence Modifier.

Ability Score Increase

Your Intelligence score increases by 2 and your Charisma and Wisdom scores increase by 1.

Age

An Illithid's average lifespan is approximately 135 years. Near the end of their life cycle, they will merge with the Elder Brain and become part of it.

Alignment

Mind flayers were tyrants, slavers, and planar voyagers. Illithid are usually Lawful Evil.

Innate Spellcasting (Psionics)

Illithids are natural spellcasters due to their innate psionics. They may cast certain spells, without requiring components.

You know the Mage Hand cantrip. When you use this cantrip, the hand is invisible. At level 3, you can cast Detect Thoughts and Levitate at will. At level 13, you can cast Plane Shift once per day, requiring no material components. At level 15, you can cast Dominate Monster once per day.

Superior Darkvision

Illithids are born in darkness and live in the darkest corners of the world; you have superior vision in dark and dim conditions. You can see in dim light within 120 feet of you as if it were bright light, and in darkness as if it were dim light.

Tentacles

Your unarmed strikes deal 1d4 psychic damage as you attack with your tentacles on your mouth when you hit.

Extract Brain

While a creature that has a brain is restrained, Incapacitated, or Grappled by you, you can use your Action to surround its head with your tentacles and cause 2d10 damage to it. When its health is 0, you may use another action to devour its brain. When you do, you can learn one piece of information that the creature knew. Roll an Investigation check, and on a success, you learn what you want to know if the creature knows it. You also gain 1d4 hit points providing the creature had an intelligence of 5 or higher.

Languages

You can speak, read, and write Deep Speech, Undercommon and can read and write in Qualith, the Illithid way of writing that can only be read through touch with your tentacles.