This article was first broadcast in Episode Two Hundred and Forty One on 14th June, 2023.
Note: This article was adapted from an episode script, and so there may be parts that don’t flow well when read, because they were initially designed for broadcast.
Kruthiks are an odd bunch.
D&D is always generally set in a late medieval or early renaissance feeling setting, occasionally verging into the age of steam for technology when you’re talking about Eberron, but it usually stays firmly in the realm of fantasy.
Which makes Kruthiks a little odd in a meta sense. Species of burrowing, oversized, insect-like creatures with swarming behavior and a loose hive mind are not a new trope by any means, but they’re usually placed in science fiction tales, often when the story needs an enemy numerous, alien, and unintelligent enough that the good guys can indiscriminately destroy them without guilt.
Another unique thing about Kruthiks is they’re creatures that managed to hit their stride in 4th edition, but they’ve continued on in the game.
Technically, the chittering chompers snuck in at the very end of edition 3.5. In 2003, Wizards put out a sourcebook called the “Miniatures Handbook” that focused on rules to support army-scale conflicts, in sort of a callback to D&D’s wargaming roots. To support that, they introduced a bunch of creatures that would function as regular opponents for characters, but also had a better than average chance of showing up in huge hoards to support the army-scale battles. The Kruthiks were listed as a magically created species that lived in hives and had a 5-10 year life cycle and came in small, medium, or large size. Literally.
Fourth edition was where their existence, origins, and behavior were really fleshed out. For those who don’t remember, the lore of fourth edition focused heavily on a world called Nerath, where ancient empires of dragonborn and tieflings ruled until a massive war between them destroyed their civilizations. The Kruthiks were blamed on the tieflings, and they made it into the first monster manual for 4th edition. There wasn’t a lot done with them after that, but they did have the dubious honor of being a focus of the very last edition of Dragon magazine published.
They made it into the first monster manual for 5th edition too, although as with most creatures a lot of the lore that had been built up for them was stripped out, most likely because of how much it tied into 4th edition’s setting. They’re still swarming, hive-like monstrosities, but the tiefling empire connection was dropped.
Originally the reason the kruthiks existed at all was because the warring tieflings wanted creatures that could dig under and through enemy walls, then cause destruction and havoc after that job was done. So they got one of the devils they’d all sold their souls to and he showed them how to take scytheclaw drakes and magically merge them with insects.
Kruthiks are mostly reptilian with insectoid behavior patterns. They have two major limbs that are forward and back of their bodies, with more articulated limbs between them. They have elongated oviod bodies and long necks. Their heads are full of spiny teeth and have ridged plates of chitin, which also cover most of their body. Star Wars fans may look at them and compare them to the creature that attacked Obi-Wan in Attack of the clones.
They are considered sapient, but it’s debatable. They seem to show some understanding if someone is speaking infernal, and they communicate with each other, but that communication is usually clicks, hisses, and possibly some pheromone exchanges. People debate if they’re actually intelligent enough to comprehend languages, or if they just have comprehension at the level of dogs or similar.
Of course, not a lot of people are interested in finding out if they’re intelligent because they’d really prefer to just exterminate them. Kruthiks do their original job very well, so they will routinely tunnel into areas, eat or otherwise tear apart whatever is living there, and then try to set up a nest to make more of them.
Unsurprisingly, where they do this a lot is in the Underdark, since things burrowing through the walls and setting up houses is practically a hobby for creatures down there. Kruthiks usually make nest building the first priority whenever they get to a new space that suits them. They expand whatever location they’re going to make their central living area, and whichever members of the hive aren’t doing that go out and hunt for food. Kruthiks are carnivores. They will eat carrion, but they prefer fresh prey. Another interesting thing some hives will do is herd any oozes or elementals they encounter and get them to help in guarding the nest.
Kruthiks will defend their nest viciously, but unlike many creatures, they aren’t doing it to protect their eggs. Kruthiks lay eggs only once a year, and they hatch after a couple of days. The youngest Kruthiks are the size of large dogs and fully capable of tearing a humanoid apart from birth. It takes them a year to grow into adulthood, where they average six feet tall and 250 pounds and develop the ability to fling spikes from their body.
After 5-10 years, if the kruthik survives, it will form into a cocoon for several weeks. After it’s finished, it will emerge as a larger kruthik that can spit acid along with the rest of its abilities. These are hive lords.
Hive lords are the undisputed rulers of the hive. This seems to be part of their biological makeup. There are no dominance fights between members of the hive; they just accept the hive lord as the one in charge. On the rare occasions where there is more than one hive lord, the oldest one is the one in charge.
The larger a hive gets, the more dangerous it seems to be, which makes people think there is some sort of hive-mind ability with the creatures. Large groups of kruthiks will flank prey, collapse tunnels to stall or trap intruders, and set up efficient rotations for digging out and expanding their nests. There’s also the ooze herding behavior. In contrast, singular or small groups of kruthiks out hunting often seem instinctive in their behavior, attacking until they take too many wounds and then simply running. Also, killing the hive lord seems to be a catastrophic signal. Even if a hive has a very advantageous and built-out nest in a location, if the hive lord is killed in any way the whole hive will pack up and relocate, as if the old site is tainted.
Relatedly, kruthiks do seem averse to the sight and especially the smell of their own dead. Kruthik blood and ichor become very lucrative merchandise in areas where kruthiks are common. Also, because kruthiks have a habit of dragging their kills back to their nest, all of the unfortunate victims’ gear gets dragged along. Clearing out a nest or finding an abandoned one can therefore be quite rewarding, and is the reason many adventuring parties will consider taking jobs to exterminate them. The tunnels and caves they leave behind are also conveniently sized for many humanoids, so if the threat is truly gone, some groups decide to move in afterward.
Working Kruthiks into a campaign is not hard at all; they were more or less designed to be another creature it was plausible to find in dungeons. Any campaign in the Underdark can feature them at any point, and their in-universe habit of tunneling around until they find a nice area to set up a nest means they could be randomly present in any dungeon with a respectable underground.
Kruthiks in the monster manual are CR2, so they’re easy options to throw against lower level adventuring parties. You’ll want to pay attention to how many of them there are, however; Kruthiks have pack tactics by default, so a straight up fight with one can suddenly turn into a punishing slog if two or more friends show up. Hive Lords also have a very dangerous AOE attack that can ruin an incautious party in short order.
So if you’re tired of filling your caves and dungeons with yet more goblins, kobolds, and giant spiders and want something a little different, take a look at Kruthiks.
