Mind Flayer 5e: The Psionic Secrets of Illithids, Revealed

Medium Aberration, Lawful Evil 

Armour Class: 15 (Breastplate)

Hit Points: 71 (13d8 + 13)

Speed: 30 ft.

11 (+0)12 (+1)12 (+1)19 (+4)17 (+3)17 (+3)

Saving Throws: INT +7, WIS +6, CHA +6

Skills: Arcana +7, Deception +6, Insight +6, Perception+6, Persuasion +6, Stealth +4

Senses: Darkvision 120 ft. Passive Perception 16

Languages: Deep Speech, Telepathy 120 ft. Undercommon

Proficiency: +3

Challenge: 7 (2,900 XP)

Magic Resistance.
Mind Flayers have advantage on saving throws against spells and magical effects.

Innate Spellcasting (Psionics).
Mind Flayers can cast the following spells, requiring no materials. Their modifier is Intelligence (Spell Save DC 15).

At will: detect thoughts, levitate

1/day each: dominate monster, plane shift (self only)


The Mind Flayer makes a melee weapon attack against one creature (+7 to hit, 5 ft. reach, 15 or 2d10 + 4 psychic damage). Medium or smaller targets must succeed a DC 15 Intelligence saving throw or be grappled. Grappled creatures are stunned until the grapple ends (escape DC 15).

Extract Brain.
The Mind Flayer makes a melee weapon attack against one creature affected by its grapple (+7 to hit, 5 ft. reach, 55 or 10d10 piercing damage.) If the target is killed, the Mind Flayer extracts and devours its brain.

Mind Blast (Recharge 5–6).
The Mind Flayer emits psychic energy in a 60-foot cone. Each creature in the area must succeed on a DC 15 Intelligence save or take 22 (4d8 + 4) psychic damage and be stunned for 1 minute. Stunned creatures can repeat the saving throw to end the effect early.

Monster Manual, pg. 222

What is a Mind Flayer?

Mind Flayers, also known as Illithids, are Psionic Aberrations that are about the same size as a humanoid but look nothing like us, and for good reasons… they like to snack on our brains.

They’ve got the appearance of a purplish humanoid with a squid on its face, and a Mind Flayer who is well-fed on a nutritious diet of brains will be coated in a thin layer of mucus. Charming, I know.

The Mind Flayers can best be described as the “scourge of sentience” as they subsist off humanoid brains and tend towards tyrannical enslavement of the sentient creatures they encounter.

Mind Flayers experience euphoria when consuming the brains of their prey. In doing so, they can access all that was stored within the brain, to begin with, knowledge and memories, as well as essential enzymes, hormones, and psychic power.

The Mind Flayers once controlled vast empires all over the multiverse. Their conjoined consciousness as a hivemind made them powerful. They could plan far-reaching plans from across the galaxy without ever leaving their current locations.

The Mind Flayers would subjugate other sentient species, warping them to unrecognizable states. The Grimlocks and Kuo-Toa are among the many races touched by the Mind Flayers.

These races were once slaves to the Mind Flayers, existing for the nourishment and protection of their masters. Eventually, their empires fell, and the Mind Flayers were driven to the depths of the Underdark, where they reside to this day.

Mind Flayers are psionic commanders who use their psychic powers to control humanoid beings like Grimlocks and Ogres. Creatures under their control are like physical extensions of the Mind Flayer’s self, obedient thralls acting for only the good of their master.

Mind Flayers avoid direct confrontation, preferring to send their thralls after a threat before escaping to safety. They will fight only if it is essential.

A Look Into the Mind of a Mind Flayer

Mind Flayers are viciously arrogant creatures, believing other lifeforms to be inherently lesser than themselves. They view other lifeforms as one of three things: food to be eaten, slaves to serve them, or vessels to infect to produce more Mind Flayers.

They are cold, calculating, and pragmatic to a fault. Though Mind Flayers seem unemotional and calm to an outsider, they actually feel a full spectrum of emotion and feel it pretty intensely.

These emotions can drive Mind Flayers to act out irrationally, even though their visage is that of an oppressive and composed tyrant.

Mind Flayers are unmatched in cruelty and sadism. They’re wholly evil creatures that care not for the pain they cause to other creatures. Despite this, they’re profoundly paranoid and suspicious of others. They’ve long been hunted, and so their primary concern is survival and concealment.

Though they exist as a hivemind, Mind Flayers are individuals with their own thoughts and feelings. No two Mind Flayers are exactly alike. Their emotions and ideas are influenced not just by the Mind Flayer’s own experiences but also by the experiences of the creatures they consume.

Mind Flayer society puts a lot of emphasis on “order.” Still, the Mind Flayers are intensely competitive creatures that, at times, could be hesitant to work together as a team.

However, this competitiveness ultimately served to better their society as their incredible intelligence allows them to see that to achieve what they want, they must put their differences aside for their own idea of “the greater good.”

Mind Flayer Society

Society is a strong word when it comes to Mind Flayers. They live in hivemind colonies of sibling Mind Flayers devoted to an Elder Brain, which consists of all the brains of fallen Mind Flayers in the community.

The Elder Brain telepathically controls all the Mind Flayers in a particular colony.

The Elder Brain telepathically communicates its desires to all Mind Flayers in a 5-mile radius around it individually. It can hold multiple conversations at once and may interact with each Mind Flayer separately and independently.

Like their Elder Brains, Mind Flayers prefer to communicate using their telepathic powers but can speak if needed. The colonies live in communities surrounding a briny pool that houses their Elder Brain.

Mind Flayers are rarely, if ever, seen alone. At best, a Mind Flayer will be flanked by at least two slaves who do all of their biddings. Enslaved races include Ogres, Troglodytes, Grimlocks, and other species that the Mind Flayers view as “inedible.” 

The population of enslaved peoples in Mind Flayer colonies vastly outnumbers the population of Mind Flayers. Oryndoll, an Illithid city, had a population of about 24,000, but less than 5,000 of those people were Mind Flayers.

Rogue and loner Mind Flayers are unusual at best. As a race with a collective consciousness, it’s impossible to become separate from the whole. Solitary Mind Flayers are outcasts, rejected by the collective, even if they will never truly be separated from them.

Renegade Illithids

Though Mind Flayers are a hivemind race, Mind Flayers which stay outside of their Elder Brain’s range of control for long enough can regain their free will. These “renegade Illithids” may go on to establish their own colonies or seek out friendships and alliances with other races. 

However, all of these changes would be null and void if the renegade Illithid were to fall back under the control of an Elder Brain.

Mind Flayer Reproduction

Mind Flayer reproduction is pretty horrifying. Mind Flayers are sexless, bearing no semblance of conceptual male or femaleness. 

Once or twice in their lifetime, a Mind Flayer will lay a clutch of eggs that will hatch into tadpoles. These tadpoles would be kept in the tank of their Elder Brain, which feeds upon the tadpoles.

The tadpoles are fed brains by caretakers and, when lacking sufficient brains to feed on, would engage in cannibalism to survive. The tadpoles that survive for about ten years will breed the next generation of Mind Flayers. 

Mind Flayers reproduce using a process called ceremorphosis or the transformation of the brain. A humanoid creature is first infected with a Mind Flayer’s tadpole.

The tadpole then consumes the brain of the humanoid and transforms them into a Mind Flayer over time. Some creatures can resist the transformation, and a select few can even reject it.

Not all humanoids are considered fit for the implantation of a tadpole. Those that are unfit are usually enslaved rather than eaten or morphed.

Mind Flayer Names

Mind Flayer names are an assortment of words, thoughts, and images that could be used to identify one Mind Flayer to their community. These names are far too complicated to be translatable to any everyday speech.

However, some Mind Flayers would adopt names that were easier to pronounce for the convenience of their thralls or as a psychological tool to strike fear into their enemies’ hearts.

A Player’s Guide to Hunting Mind Flayers

Players should be careful when engaging with Mind Flayer. Mind Flayers do not wish to engage in combat, so a Mind Flayer looking for a fight is looking for one for a reason. 

Mind Flayers can deal incredible burst damage both to a single target and in an area of effect. Their propensity to immobilize their targets makes them a massive threat to any creature in melee range.

The Mind Flayer’s grapple is much stronger than the regular grapple. It inflicts a hard stun rather than simply reducing speed to 0. Besides attempting to end the grapple, no actions can be taken after being stunned by a Mind Flayer’s grapple.

However, their significant damage comes at a cost. The Mind Flayer is a somewhat fragile creature that can be felled quickly when pelted with high damage spells and weapon attacks.

The trick is to get in there and kill the Mind Flayer before it has a chance to rain Hells upon you.

Players who are facing a Mind Flayer will want to end the fight as soon as possible. Mind Flayers fare better in long fights where they can land stuns with their Mind Blast and Tentacle attacks. The faster the fight ends, the easier it will be to kill a Mind Flayer.

Mind Flayer Damage Breakdown

Mind Flayers come armed with three damaging abilities. Their tentacles (15 damage, average), their Extract Brain (55 damage, average), and their Mind Blast (22 damage average).

Both their tentacles and Mind Blast can inflict a stun as well. This skill list is a very lethal combination of abilities packing high burst damage with powerful control abilities.

Remember that Mind Flayers aren’t primary casters. Their Spell Save DC is deceptively low since it doesn’t really matter for anything except Dominate Monster, which can’t be used on players anyway. Their low DC is compensated for because Intelligence is a dump stat for most classes in 5e.

Mind Flayers will be outputting about 38 [((22*2)+15+55)/3] damage per round which is enough to be threatening to a Barbarian even if they had the maximum possible hit point pool they could have at 7th level (144).

Landing even one grapple on a Barbarian is practically lethal since two average hits of Extract Brain will virtually kill them.

Assuming the characters are at the 7th level when they fight the Mind Flayer — so about evenly matched with it — a Mind Flayer can kill a Wizard in 2 rounds, a Cleric in 3 rounds, and a Barbarian in 4 rounds.

So it’s critical for players to start and close the fight as quickly as they can to avoid anyone’s brains becoming a healthy breakfast.

A Dungeon Master’s Guide to Mind Flayers

Mind Flayers are a group of creatures who will want a parley if they can have one. They’re not exactly pacifists, but they don’t want to be in danger and would rather come to agreeable terms for both sides to avoid violent conflict.

When faced with resistance, they will flee rather than fight a senseless battle. 

Mind Flayers may make good allies as they have vast pools of knowledge and experience because they can know and experience what their prey did before them.

This expanse of knowledge is shared amongst the collective since their consciousnesses are all connected, and they can ask around about information with ease.

A Mind Flayer might make an exceptional advisor for information trading, much like a Sibirex. A Mind Flayer’s prices are not going to be as simple as the Sibirex’s, though. Sibirexes can be tempted with shiny, valuable objects, further knowledge, or even assistance with tasks. 

Mind Flayers are not so easy to please. Simply put, they want something pragmatic to them like slaves that they can breed like livestock with the purpose of consuming their brains and morphing them into more Mind Flayers.

Mind Flayers have no use for the coin, but they do have use for the brains and bodies of humanoids.

In battle, Mind Flayers will rarely be seen alone. As a hivemind, they are more than willing to protect their collective. A Mind Flayer in danger may call for its allies, who will almost certainly respond.

Even if no other Mind Flayers are available, most Mind Flayers have their own group of thralls, ogres, troglodytes, and other creatures that they have control over.

These creatures will fight to the death for their masters. They have no free will and are mere slaves to the Mind Flayer. The Mind Flayer doesn’t have empathy for them either and will throw their lives away without hesitation to preserve itself.

Incorporating a Mind Flayer fight takes some finesse and prior planning. As previously stated, they’re not solitary creatures at all, and there’s virtually no way for an average party to reasonably expect to take down a whole colony of Mind Flayers by themselves. 

However, there are some solitary Mind Flayers, though not by their own choice. A rogue Mind Flayer who has been rejected by Mind Flayer society will be motivated to attack a party. When living in a colony, the colony works together to provide the necessities, but as a lone wolf, this Mind Flayer will need to hunt for its food.

A Mind Flayer living in a colony may have slaves bred for eating, but a Mind Flayer with no colony might attack players simply because they’re starving. The brains of sentient creatures aren’t exactly something you can purchase at Wal-Mart. This Mind Flayer may act in desperation to try and feed themselves.

Mind Flayers as a Playable Race

Mind Flayers are not currently a playable race in any official sourcebook. DMs Guild author Zavier Bates has created a supplemental race in his Forgotten Gifts book, including a “Half-Mind-Flayer” race. These creatures are humanoids whose bodies rejected the ceremorphosis and left them in a sort of half-and-half state.

Baldur’s Gate III, a video game based on the Dungeons & Dragons universe, also features player characters who have been infected with Mind Flayer tadpoles. They are able, at first, to resist the transformation, but for how long and at what cost?

Perhaps in the future, we will see Mind Flayers as a playable race. The inclusion of Mind Flayer ceremorphosis in Baldur’s Gate is a promising sign, at least, but I wouldn’t get your hopes up just yet.

Due to the threat of a renegade Illithid being brought back under the control of an Elder Brain, their inclusion as a playable race would be risky for players and GMs alike.


Mind Flayers are a fantastic look into the side of cold, cruel evil. They make great flat villains because they’re so morally uncomplicated; their actions, beliefs, and society are wholly objectionable to most people.

Whether your Mind Flayers are tyrannical villains or sadistic advisors, there’s no shortage of unique ways to incorporate these Eldritch horrors. Happy questing!