E. Gary Gygax, one of the original minds behind Dungeons and Dragons, has been called a lot of names: difficult, driven, brilliant, obnoxious, nerdy, clever ... But even Gygax's worst detractors agree that D & D was one of the most influential game systems ever.
One of Gygax's ideas from the very beginning was to inject his game world with a lot of variety—a depth and breadth that would lend a greater feeling of realism to the fantasy gaming world. One way that D & D achieved this verisimilitude was by carefully varying the way things are named—rather than just having magical rings, Gygax dusted off his thesaurus and added diadems, bracers, pendants, talismans and a whole lot more. He even pulled out a few seldom-used words like phylactery, libram and philter (he seems to have coined a term or two as well).
When it came to populating his world with monsters, Mr. Gygax was no less creative. The earliest D & D books included no less than five amorphous nasties (think the Blob), each with specific strengths and weaknesses. Rather than naming them "blue blob" and "red blob," and so forth, Gygax and company showed their usual panache with a remarkable variety of weird creatures to plague would-be wizards and warriors: grey ooze, ochre jelly, green slime, yellow mold, and many more.
When the Eldrich Wizardry supplement was released in 1976, psychic powers (Gygax and company chose the obscure and wonderful term psionics) were added to the mix. In order to make the psionic game interesting, they needed some villains. In addition to fitting out some of the old monsters with psionic powers, they added a new crop of baddies. Gygax's thesaurus came through again, there were intellect devourers, brain moles, thought eaters ... and then there were the mind flayers.
Mind flayers are human-shaped creatures of exceptional repulsiveness. With a tentacled mouth, their head is like a four-armed octopus, their lanky bodies are purple and slimy—the overall effect is creepy and grotesque in the extreme. They live deep underground, and whispered rumours tell of a vast mind flayer civilization. It is probably not surprising that the brain mole did not capture players' imaginations, but these fellows did, in a big way.
Mind flayers are dreadfully powerful, with their hit points and armor class being higher than ogres, most giants and even some demons and dragons. Mind flayers are smarter than the majority of player characters (genius-level intelligence, which is equivalent to a stat roll of 17 or better). They are able to see in the dark and have a number of powers related to their psionics (including a 90% resistance to magic spells). Their psionic attack can paralyze characters, then the flayer can use its tentacles to pull the brains out of the dungeon delvers' heads and gobble them down!
Their horrible appearance and repulsive dietary habits made these monsters an instant hit with teenaged boys. If your character had to die (and so many did!), what better way to gross out your friends than to vividly describe how the mind flayers paralyzed him and devoured his brain? The absurd level of power that these creatures possessed made them darlings (if mauve, octopus-faced underground carnivores can ever be anyone's darlings) of dungeon masters everywhere. Gamers getting a little too big for their britches? Cull the herd with a few mind flayer attacks!
The mind flayers were appealing for reasons apart from their ability to make a grisly end of obnoxious players. There is something wonderfully creepy about a weird race of underground guys who look like Cthulhu and are smarter and tougher than your characters are. They were also a lot of fun for the artistic types to draw, what with all those tentacles waving around like that. Players and DMs alike enjoyed imagining what the mind flayer civilization may be like; the books hinted at huge underground cities and
dungeon masters (yours truly included) spent loads of time (which might have otherwise been wasted on such useless pursuits as studying or chasing girls) in creating elaborate conspiracies between mind flayers and other subterranean denizens.
In later editions of the game, these creatures got fleshed out a little bit. We learned that 'mind flayer' is just the name humans and other such surface dwellers use for these nasty beasties. The name they call themselves (because, let's face it, very few would actually choose to call themselves something like mind flayers) is illithid (which is appropriately Lovecraftian-sounding, I think). We learned that they are warm-blooded amphibians which hatch from eggs and live in a tadpole state for about ten years, before gaining legs and an erect posture. Illithids live in communities with their slaves (usually intelligent creatures that they have used their mojo on to brainwash), and that the center of their community is the elder-brain. This is where the D & D guys really come through in the imaginative gross-out department. The elder-brain is a huge pool of fluid containing the brains of deceased mind flayers. This disgusting mess (or noisome tarn, as Gygax might perhaps term it) is sentient and acts as a kind of community overmind, warning center, and wise elder for the illithid village.
Later, one of the many designers of the wonderful game NetHack decided to include mind flayers among the tough monsters that inhabited the depths of the dungeons. They were a memorable part of the game—I am sure that many of us remember being absolutely terrified by a lowercase h (for humanoid) on our screen. But the mind flayers' legacy continues, they have appeared in games such as Neverwinter_Nights and Baldur's Gate. In Final Fantasy V, a similar icky creature called Mind Flare challenges characters in the final dungeon and recently the hilarious online game the Kingdom of Loathing, with its many spoofs, homages and send-ups, pays its own form of weird tribute to NetHack (and thus, indirectly, to D & D). In the Dungeon of Doom (where everything looks like an ASCII character) you can fight against mind flayers. They look like lowercase h's of course, and it is even possible (as it was in NetHack) to eat the dead mind flayer after you win the fight. If you do, you will get the following message:
"You eat the mind flayer, and feel yourself becoming more mindful. It’s a good thing you didn’t eat a deceit flayer, or a venge flayer."
It has been almost three decades since the illustrious Mr. Gygax set his mauve monstrosities loose on the unsuspecting gamers of the world—that's a pretty good run in most anyone's estimation, and who knows where his creations may show up next—maybe someone will even include brain moles in an online game someday!
References:
Gygax, Gary and Blume, Brian, "Eldrich Wizardry" (TSR Rules, Lake Geneva, Wisconsin, 1976).
Gygax, Gary, "Monster Manual" (TSR Rules, Lake Geneva, Wisconsin, 1978).
TSR Inc., "Monstrous Compendium" (TSR, Inc., Lake Geneva, Wisconsin, 1989).
Chrisomalis, Stephen, "Linguistic Disquisitions" at the Phrontistery: http://phrontistery.info/disq6.html
Plus many years of playing these games, reading the Dragon magazine and talking with D & D players