With Baldurs Gate 3 within spitting distance of release, it might be a good time to look at what seems to be the antagonist of the game, Mindflayers (also known as Illithid). For those who don't know, these creatures have purple skin and look like someone swapped their face for an octopus.
Their weird Cthulu face isn't all there is to know about them, however. They have been around since the earliest editions of D&D and haven't gotten any less nasty. In fact, their history is fascinating and they have had quite an impact on the lore and planes of the D&D universe. Here are a few things you probably didn't know about them.
10 They Are Responsible For The Rise Of The Gith
The Gith are playable species in 5e and if you're playing one you have a choice between Githyanki and Githzerai. There's a reason for there being two different types, and that's because they had a bit of a civil war. That civil war was based on a dispute on how they should use the power of the Mindflayers after they successfully rebelled against the purple squid people.
Yup, turns the Gith were a slave race like many others to the Mindflayers, the Gith were just lucky and numerous enough to mount a successful revolution. The Gith successfully killed pretty much all the Mindflayers in their revolution and still hunt the remaining ones to this day. The Mindflayers had a vast empire till the Gith took it away, but it hasn't stopped the remaining Mindflayers from slaving other humanoids still.
9 The Mindflayers Have Slaves
Mindflayers heavily rely on slaves in their society which they use for a variety of different things. Just because Mindflayers reside in the Underdark right now doesn't mean they just adopt the practice of slaving from other denizens of the underworld. They Have been long time practitioners of finding and taking different humanoids to use in their colonies.
Slaves come in a variety of forms for the Mindflayers, but they really prefer to have medium-sized humanoid slaves. So they actively go after elves, humans, and anything of similar stature. The Gith may have been their previously preferred type of slave, now they aren't so picky. This choice to use Medium-sized creatures isn't a stylistic choice on their part either, no, this plays into their reproductive cycle.
8 Mindflayers Are Actually Tadpoles In There Original State
Much like alien creatures, Mindflayers need to grow inside something else till they are mature. This can only really grow into a true Mindflayer inside of a medium-sized creature, 5-6 feet or so and 130-230 Pounds give or take. Until they complete this process they are functionally a strange tadpole leach like being that lives in brine.
That brine they exist in till they are placed in a host is a fluid composed of other deceased Mindflayers. So, you know, 100% not creepy their swimming around in what could be their liquified grandparents. That being said Mindflayers lay eggs in vast quantities into these pools to hatch and then grow, making them very alien.
7 The Mindflayer Tadpoles "Transform" Their Hosts (Ceremorphisis)
They grow inside something else as previously states, but they get to where they want in their host by going through the eye. The Mindflayer tunnels underneath the person's eye socket and into their brain, where they latch onto their brain and begin to consume them. Over time the person will slowly lose control of themselves, and at a specific point, the victim's head will burst as the tentacled purple octopus head replaces it. Some people may not even know it's happening until its too late.
6 They Are Better At Psionics Then Spell Casters
The Mindflayer isn't actually that accomplished of a spell caster, it is far better at using psionics (mind magic basically). It frequently will use its psionic mind blast ability to stun and make someone lose control briefly so that they can approach and attack. Their psionic power also gives them a variety of mind effecting abilities like levitation and reading the thoughts of others.
The Mindflayer is still a fantastic spell caster that is functionally considered to be 10th level caster on paper. There's always been a reason they are considered extremely dangerous, this one of them, the other is they like brains, a lot.
5 They Probably Want To Eat Your Brains
If you meet a Mindflayer in the Underdark, the vast majority of the time they're going to want to eat your brains. It's an absolute necessity for them to live, if they don't get brains they die. Buried beneath that mass of tentacles is a hole with very nasty teeth which they could use to crack open the skulls of their victims and suck out their grey matter.
Eating brains can make them more dangerous in-game, as it gives them some insight into their snack's personal history. If one hero is devoured, it will give the Mindflayer knowledge on the adventurer's companion's habits and abilities.
4 They Live In Colony's
As if one wasn't bad enough, if you find one Mindflayer there's a strong possibility there are more. Though it's not impossible that a Mindflayer might strike out on their own, it's more likely that there's a colony nearby. They develop underground lairs that have a variety of purposes, experimentation, enslavement, and safety.
Mindflayer colonies can be found near other humanoid settlements as they Mindflayers will need consistent access to brains. This makes them detrimental to all other species, as they will simply prey on them. These colonies form around an elder brain which governs the colony and generally directs its actions.
3 They Like To Experiment On Other Creatures
Mindflayers aren't just brain-eating monsters, they are equal parts mad scientist. Taking slaves and putting their offspring in them they will try to experiment on the humanoid in order to produce different creatures. By actively doing this they create other thralls and monsters that perform a variety of services for them. This has resulted in the creation of things like the mind worm and intellect devourers. It's important for their reproduction process and to find a means to recoup their losses from their ancient war with the Gith.
2 They Have (Had) Massive Flying Ships
These ships are called spell jammers and are massive squid looking things that resemble a Nautilus. They can fly, teleport, and go into space (like outer space). The ship has long tentacles at its front which can grab and pull things closer to the ship itself. This makes it easier for their crew to board other vessels, or snatch people off the ground.
Most of the spelljammer ships were destroyed when the Gith rebelled and nearly caused the extinction of the Mindflayers. It's a very good thing these ships are few and far between, Mindflayers having access to a floating teleporting bases is very much the stuff of nightmares.
1 They Might Be Future Aliens
This is speculation and unconfirmed but fits like a glove. The Aboleth are the oldest creatures in D&D (in theory). They inherit the memory of their parents with perfect recollection and know the place and time that every species was created. Why is this important? They don't know when or when the Mindflayers were created.
If they remember all the species creations, except one, it stands to reason that that 'one' hasn't happened yet. The Mindflayers supposedly controlled an empire that spanned a number of planes before it fell, and traveled through space on their spelljammers. They are definitely alien in nature, whether they are from the future is unconfirmed, but it's kind of the only explanation here that works.
So, ya, they're 100% scary, what do you think?