10 Mind Flayer Story Ideas for the Devious DM

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Ever since I played Baldur’s Gate 2 as a kid, I’ve been fascinated and terrified of Mind Flayers. I love encountering them as a player, and I relish using them as a DM. I want to share some of my better ideas for implementing Mind Flayers in a game so I can spread the Illithid gospel and see them used often.

Here are my ten titular tips and tutorials for trying tentacled Mind Flayers in your tale! (in no particular order).

#1 Mind Flayer Idea – Arcane Cerebral Thief

Wizards specializing in a variety of magical schools are being murdered. The killer decapitates the wizards, taking the heads while their bodies are left behind. The culprit is a renegade Mind Flayer. This bad boy is feasting on the magical secrets within the minds of wizards. His goal is to grow his own arcane prowess in order to survive on his own since his colony was wiped out. An alternative motive would be that he once consumed a wizard’s mind and became addicted to the taboo arcane arts, earning him exile from his colony.

I recommend creating NPC wizards that each specialize in a particular school of magic. Players could choose to investigate this as a side quest, allowing them to meet the NPC wizards along the way. Think about hints you can drop along the way as to the reason the victims’ heads are missing. I also recommend using a city that has a river running through it since a Mind Flayer could use it to stay hydrated while reliably escaping unnoticed. I leave it up to you whether or not the wizards’ spellbooks are taken or left behind at the crime scene.

When the players finally encounter this murderer, they may not have deduced that the murderer is a Mind Flayer. This will likely surprise them and make them wet their pants when they realize they are confronting an Illithid that can cast arcane spells to an undetermined degree. You could also sow distrust and misinformation by allowing the murderous Mind Flayer to enthrall someone of importance in the city guard to help him attack at opportune times and escape in unpatrolled parts of a town. Players might notice a pattern that leads them to believe the murderer is part of the city guard or has an ally within it.

A confrontation could take the form of a stakeout as the party lays in wait at the wizard tower of an NPC they’ve deduced to be the next intended victim. I suggest playing up the stealth and fear as a long shadow enters the area, followed by silencing of their thoughts as the Mind Flayers unleashes psychic interference. It would also be cool if the Mind Flayer, drunk on arcane power, had trippy eyeball patterns like Kaa from The Jungle Book when he uses hypnosis. Hypnotic Pattern would be a spell worthy of this arcanist Mind Flayer. Reverse Gravity would also be cool. I’m sure you can imagine heaps of spells that would fit the situation. Get creative!

#2 Mind Flayer Idea – Eugenics

Cereomorphis is the process by which Mind Flayers reproduce, hatching tadpole-like creatures that parasitically insert themselves into the skulls of victims. The tadpoles devour the unfortunate hosts’ brains, after which the tadpoles attach to host bodies’ brain stems to begin functioning as a replacement brain. The acquired body begins to morph over the course of about a week to become a Mind Flayer. This process is elaborated in Volo’s Guide to Monsters p.72.

This is a cool concept that reminds me of the critters from Star Trek that would crawl into ears and force hosts to speak honestly. I’m also reminded of the xenomorph from the Alien movie franchise, though a Slaad bears more resemblance to chest-bursting than Mind Flayers. The Alien series, however, offers an interesting concept in that newborn xenomorphs will take different forms based on the creatures they spawned from. I’d like to borrow this concept. Mind Flayer reproduction can produce interesting evolutions based on the races they overtake. A Mind Flayer born from the body of a Yuan-ti may resist poisonous effects or have an elongated body. Other Mind Flayers born from Kenku may have exaggerated beaks that can mimic speech.

Illithids might seek out particular races in order to assimilate their special powers into the newborn Illithids, much like the Borg do in Star Trek. For this purpose, you could introduce a plot where Mind Flayers are seeking to find an ancient race in order to assimilate their genetics and gain their legendary knowledge. Creatures that come to mind include Sphinxes, Aboleths, Couatls, Dragons, or Treants. Picture any of these races transformed to resemble Mind Flayers and you have yourself a nightmarish monster for your players to encounter.

Give your players a duty to protect the whereabouts of ancient creatures to prevent Illithids from assimilating their genetics and knowledge. The stakes could involve the prevention of Mind Flayers gaining secrets to immortality, time travel, or godhood. Perhaps the Mind Flayers are trying to return to their mysterious home in a lost place of existence, but there are ancient creatures who remember the origins of the Mind Flayers. It may also be possible that the Mind Flayers are merely seeking to perfect their physical selves through Eugenics, and thus must be prevented from obtaining more-perfected bodies of powerful creatures.

#3 Mind Flayer Idea – Deadly Interrogation

I once ran a game with a grand city where magic was restricted by the government (I know, very original). The party was captured and sent to the anti-magic prison. While imprisoned, the party witnessed an inmate being interrogated without giving up information. The guards brought in a Mind Flayer that had a metal cap on its head to disable its psionic attacks. While tied up, the Mind Flayer seemed to be starving as it was ravenously unleashed on the interrogated prisoner, consuming his mind. It was assumed by the party that the Mind Flayer would later tell the guards everything they wanted to learn from the interrogated prisoner.

To sum it up, Mind Flayers make for brutal interrogators. I think it’s a frightening concept to have your party members facing down captors that will unleash a Mind Flayer on them if they refuse to surrender information.

#4 Mind Flayer Idea – Culinary Killers

This will be an interesting quest for characters that have chosen proficiency with cooking. These Illithids behave almost like the Gentlemen from Buffy the Vampire Slayer, moving about with snooty arrogance as they seek out the latest cerebral delicacy to devour. They work almost like a Hag coven as they are small in number. Their motives aren’t world domination; they just want to taste the perfect brain. Cooking and seasoning might be important to them as they force victims to solve difficult math equations or read classic literature prior to feasting on their brains.

They also enthrall weak men to serve them and to find brilliant people with assumedly delicious brains and bring them to have their minds devoured. I imagine these thralls would put out job notices for translators of an ancient language, doctors of herbalist medicine, or scholarly tutors for noble-born children. This is essentially a scam like we encounter in our own world where princes from far away lands request our help or make offers that seem too good to be true.

Don’t neglect to prepare the Mind Flayers with intellectual trash talking. They should pack one-liners like Gordon Ramsey, while spitting big words effortlessly in lengthy sentences that would make the common folk faint in vocabularic destitution. They probably ought to be immaculately clean germaphobes. Their lair should contain interesting cooking components for party members to utilize when victorious, in addition to strange brain seasonings that they won’t want to touch.

#5 Mind Flayer Idea – Subconscious Culture Manifestation

Illithids who dine on the brains of a given species or culture will manifest traits from their cerebral meals. Mind Flayers will subconsciously adapt their colonies in a way that emulates the thoughts of their victims. If you have players who have played D&D long enough to know just about anything about Mind Flayers, this is an opportunity to throw a curveball.

Allow the players to encounter a colony of Mind Flayers that don’t act like the usual Illithids they’re used to. These Mind Flayers have completely replaced a settlement of Dwarves, enslaving most of the population while munching on their brains. This diet has caused them to become more brash and stubborn. Players will find that these Flayers are less like scheming masterminds and more like brutes and barbarians who enjoy rushing into battle, though with far-less brawn to back it up. The Mind Flayers might also have psychic voices that sound like Shrek.

Another example would be of a Tabaxi tribe that has been consumed by Mind Flayers, resulting in Illithids that have an intense curiosity for the unknown. These Mind Flayers may find that their colony keeps random trinkets around as trophies and souvenirs to be cherished, like hoarders that can’t throw anything away. If you want to have some fun, make these Mind Flayers have catlike fears and behaviors, such as licking themselves or scratching everything around them. Maybe they move like cats as well, slinking up to caress creatures and playing with their food.

#6 Mind Flayer Idea – Informative Funeral

Mind Flayers uphold a tradition of preserving their fallen comrades’ brains in a funerary jar. When safe to do so, a brain jar is gifted to an Elder Brain to be consumed. Brains can be preserved in these brine jars for up to forty days.

This creates an opportunity for a time-sensitive quest. Let’s say your party of adventurers is trying to gain some kind of crucial information, like evidence to bring down a corrupt politician, the location of a long-dead dragon’s hoard, or a secret to casting a powerful new spell. Well, it would be a shame if the single person that could provide any of these info nuggets to the party was somehow dispatched by a Mind Flayer. If the said person’s brain was consumed, but the Mind Flayer died soon after, the party would need to hunt down that Mind Flayer’s funerary jar to obtain the brain. That mind would hold the secrets of the mind it had consumed! It would be cool to have the players cast Detect Thoughts on a dead Mind Flayer’s brain, finding it still buzzing with thoughts to be harvested.

The challenge will be to obtain the funerary jar before the Elder Brain consumes it. Players will need to intercept and confiscate the jar before it can be returned to the deceased Flayer’s colony. As I said, this is a time-sensitive mission, so remember to impress the urgency into your players’ minds. I promise you’ll enjoy watching them attempt to plan out how they can intercept the jar before it slips out of reach.

#7 Mind Flayer Idea – Fievel Goes West

I bet this one surprised you. This is based on the kids’ movie of the same name, which involves mice living in early New York City deciding to move to the wild west of the USA to escape from a cat infestation that threatens their livelihood. It’s later discovered that the cat infestation is actually designed to drive the mice west, where they’ll be expected to build up their numbers and contribute to a town of cats that seems to want to coexist peacefully with the mice.

I’ve envisioned a scenario where Mind Flayers are using thralls to commit hate crimes against a minority group in a humanoid population. They hope to drive those people out in order to populate somewhere less fortified, somewhere safer for the Mind Flayers to prey upon them. Thralls are splendid spies that allow Mind Flayers to manipulate their enemies, so let’s use them that way. In addition to the thralls that are spreading hate crime and propaganda, there will be ‘good’ thralls that entice minorities to leave the greater population to seek a rumored new place that will accept them.

Try not to make this idea too racist because I doubt you’d enjoy roleplaying that. You could use any type of minority, whether it be a dying profession or a class system. Once the players get wind of what is happening, allow them to catch one of the hate-crime thralls meeting with its master Mind Flayer. This revelation will make your players’ eyes instantly go wide as they realize how deadly the situation is becoming. They’ll be forced to trust no one when they realize Mind Flayers have been enslaving folks. This is a milder version of my next suggestion below.

#8 Mind Flayer Idea – The Matrix

This idea is grandiose enough to encompass an entire campaign. This world has been overtaken by Mind Flayers. What is left of civilization is housed in a colossal anti-psionic bubble. This protective barrier keeps Mind Flayers, thralls, and other psionic attackers away from the citizens. In actuality, the Mind Flayers have created this “safe space” in order to farm human consciousness without wiping them out. A common problem that Mind Flayers face when they conquer a civilization is that the minds of the conquered become stagnant and scarce as they’re consumed. To prevent this brain sustenance shortage, they used their thralls to rally survivors to this one place in hopes of the barrier saving them.

The protective bubble around the city is not truly a protection, but a cage. The Illithids are constantly fed by the brain activity within the city, allowing them to constantly feed on psionic energy. This idea mimics that of The Matrix movies where humans’ minds are plugged into a cyber reality that works as a virtual reality that seems real, allowing machines to harvest energy from humans’ pods while their minds interact with the fake world known as the Matrix.

The heroes of your story could find out the truth and seek to liberate the city and build a resistance against the Mind Flayer oppressors. Some will say that they’re better off living in a fake reality if the alternative is having their brains bored out by Mind Flayer tentacles and beaks. I visualize this campaign as something like Curse of Strahd, taking place in a relatively confined area and allowing many ways to solve problems. It may be that humans try to take back their world or merely escape to another plane of existence where Mind Flayers can’t follow. Heroes can find out about the fake security of the psionic bubble from a group of Githyanki that have arrived in secret to liberate the Mind Flayers’ slaves, though with extreme measures that may scare the players into seeking their own path after gaining knowledge about the current state of things.

#9 Mind Flayer Idea – Save the Future

Mind Flayers are anomalies in the cosmos. Veteran scholars remain unsure of the Mind Flayers’ origins, but some speculate that they are from the future. The Illithids may have traveled back in time to escape calamity, gain power before others take it, or expand their empire after conquering all existence in their timeline. Let’s make a scenario where Mind Flayers are indeed time travelers from the future who have seen the end times. Your players may quest to prevent a horrible apocalypse, and the Mind Flayers’ Elder Brain is the only being that has the information the party needs to identify key creatures and characters that can cause, hasten, slow, dull, or completely prevent the end times.

This adventure demands that you develop Mind Flayer society so you can create actual Mind Flayer NPC’s and give them reasons to interact with the players. They should remain true to Mind Flayer heritage and calloused evil while still harboring their own motivations to be appeased and appealed to. I definitely recommend reading through the Mind Flayer section of Volo’s Guide to Monsters so you can create a functioning Illithid society. I also recommend that the end of the world have many moving parts to it rather than one simple answer to stop it. After all, the Mind Flayers themselves haven’t prevented the future calamity, so the solution shouldn’t be obvious. Volo’s Guide to Monsters also has tips for roleplaying Mind FLayers on page 74. I also recommend page 80 to learn about the closest concepts to a Mind Flayer’s divine philosophy and religion.

#10 – The Grand Design

Volo’s Guide to Monsters describes how a rare ceremorphosis can produce a Ulitharid, a Mind Flayer with great power and freedom from a colony’s Elder Brain. This formidable creature’s destiny is to function like a honey bee colony that thrives so much that a new queen arises and leads away much of a colony to create a new hive. The Ulitharid’s goal is to consume something like royal jelly for bees, which to Mind Flayers looks like the highborn of powerful intelligent races. Create a BBEG Ulitharid character that is leading a crusade of Mind Flayers. They don’t openly attack and reveal themselves, instead creating thralls and manipulating from the shadows to procure Elven priestesses and Dwarven king brains to feed the Ulitharid. This powerful Ulitharid will eventually become an Elder Brain if it’s not stopped.

Your party will take part in a game of wits as they try to identify which NPC’s are actually incognito Mind Flayer thralls. They’ll need to convince cities and nations to cooperate in stopping the Mind Flayer threat, but kingdoms have many other worries during a present time of war and distrust. This can be a game that balances well with political roleplaying and difficult encounters.

Alternative goals for the Ulitharid may include gaining knowledge to help the Mind Flayers combat the Githyanki that are constantly hunting Illithid colonies in the Material Plane. Artificers may provide plot devices in that their inventions are formidable weapons that Illithids can use against the Gith. To learn about Mind Flayers and their macro schemes and tactics, read page 74 of Volo’s Guide to Monsters (read the whole section of the book about Mind Flayers, but especially this page). Page 78 also describes Nautiloids, the Mind Flayers’ living ships that they use to travel the Astral Plane. You might consider using one of these ships as the Uliathrid’s stronghold of sorts. These Nautiloids are featured in the recent Baldur’s Gate 3 opening cinematic reveal trailer, if you want a visual representation.

BONUS IDEA: Cap’n Turbot

My kids like to watch Paw Patrol. I think it would be hilarious for adventurers to meet a solitary Mind Flayer that talks like the character Cap’n Turbot from Paw Patrol. He uses alliteration and big words, and his voice is nasally and nerdy. I recommend planning out tidbits of his dialogue ahead of time. Have fun with that!


I guarantee my ideas have inspired you to either implement them in your game or twist them to fit your own creative needs. Mind Flayers are iconic D&D monsters for a reason, so give them the spotlight and game time they deserve! Please, please, please comment with your own ideas so I can keep innovating the ways that I introduce Mind Flayers to my players.

Good luck with your upcoming adventures. May your Intelligence saving throws be mighty so you don’t get your brain munched by the menacing Mind Flayers.

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