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Warhammer 40K: The Most Mysterious Races Of The Grimdark

7 Minute Read
May 5 2022

Warhammer 40k has had its fair share of races that have us begging for more details. These are our favorite Mystery Races of 40k!

First off, what exactly are the Xenos?


The major alien races are the Orks, Eldar, Dark Eldar, Tyranids, Necrons and the Tau. All these races pose a considerable threat to the survival and continued dominance of mankind. There are countless other races but all are trivial by comparison.

The Imperium considers humanity the rightful rulers of the whole galaxy. Part of the Imperial Creed is that all aliens judged to pose a threat to mankind’s survival must be contained or destroyed. Aliens, along with mutants, heretics and deviants, are all considered enemies of mankind, for they threaten the very survival of the human race.

Many new alien races and civilizations are discovered by Imperial Explorators every year. For the most part, these aliens are ignored, contained, or if they present a threat to mankind or the Imperium, eradicated. Throughout its history, the Imperium has fought many long wars with dangerous alien species. In most cases, the Imperium has eventually won, but in some, the threat has only managed to be contained.

With a universe of lore the Grimdark has had it’s fair share of races that popped-up on the radar and have gone dark. Where did they go? What happened to them? Are they coming back? Frankly, we don’t know for sure. What we do know is that we’d love to see more from these races in the future.


The Slann or Slanni or even sometimes the Old Slann are a race of ancient reptilians or amphibians. The have a long history that started in the Rogue Trader Era but it was cut off around the time of 4th edition and they were quietly replaced by “The Old Ones” in the lore. Are they the same race? Maybe. Or were they also puppets of the Old Ones? Kind of depends on your sources. But what happened to them and are they still around in the Grimdark Universe? That’s the mystery!



Hrud are a pretty strange Xenos race. Some pictures (like the one above) depict them as small, sneaky creatures with flint-lock type weapons. They are almost rat-like with tails and hunched postures. Other sources have them as larger, gangly creatures which chitinous hides.

Frankly, we don’t really know which is correct – or perhaps they are BOTH correct. They have been a race that has hidden in the background and on the outskirts since their first appearance in the 3rd edition core rulebook. We’ve always wanted to know more which is why they are here on this list!


The Jokaero are an alien, ape-like race. They are master engineers and are capable of marvelous technological feats. They have been recruited by the Imperium, specifically member of the Inquisition, as Weaponsmiths. Most recently, we finally got a look at their ships which looks very different than anything else in the game:


While we have seen bits and pieces about them, the Jokaero are still a mystery. They may have been one of the races the Old Ones manipulated during the War in Heaven but they are still a mystery. Why aren’t there more of them if they are so technologically advanced? Are they hiding? Are they just scouting the galaxy? We may never find out until it’s too late.

Squats (aka Leagues of Votann)

Squats were once the most widespread of the abhuman races. They used to have an army list for Warhammer 40k with an entire range but they were “Squatted” – which is to say they were removed from the game. For the last decade remnants of them still remained sprinkled into 40K lore.

Games Workshop has recently created a few one-off Squat Minis. But SURPRISE! They are coming back in 2022 reimagined as the Leagues of Votann. The real mystery is exactly how GW will explain or retcon their disappearance for 20 years.


The Zoats are another mysterious race. Initially, they were believed to be scouts for the Tyranids. Some of the old lore had penned them as bio-constructs or a slave race. At some point the lore changed and their were Renegade Zoats that had escaped the Hive Mind. It’s unclear what function they actually serve and there is other lore that points to Zoats still being a part of the Tyranid’s fleet or at least inside the living ships of the Tyranids.

Most recently, a Zoat has been re-introduced as a part of the Blackstone Fortress. What does this mean and are there more Zoats like this one? It’s yet another mystery waiting to be solved.



For my money, the Rangda are maybe the scariest xenos race you’ve never heard of. So potent they killed off a Legion’s worth of Marines before being wiped out. Worse still, they may have been merely a slave race to a higher power! The Rangda are truly one of the Grimdark’s boogeymen. Read on for all the chilling details.

The Rangda were a violent and powerful Xenos “Cerabvore” species encountered by the Imperium during the Great Crusade. They originated from a homeworld of the same name.¬†Though now a footnote in history, the Rangdan Xenocides were a massive series of campaigns fought for Humanity’s survival. Over the campaigns 80,000 Astartes and millions of Imperial Army gave their lives to hold back the Rangda and their slave cohorts. There are subtle implications the Rangdan Xenocides may be related to the “Missing Legions & Primarchs”.

The Rangda were first encountered by the 105th Pioneer Company of the Vth Legion in the northern rim of the Galaxy and were recognized as a grave threat and engaged by the First Legion of Astartes. During the Rangdan Xenocides, the Rangdan invaded from the galactic north and east. In the bloodiest war for the Imperium until the Horus Heresy the Rangdan were halted, at great cost to the Imperium and the Dark Angels especially.

The Rangdan were described as possessing “Slaugth murder-minds”, suggesting they may have been a slave species to the Slaugth species. Indeed, the Slaugth have been seen following the wake of the Rangdan, harvesting the dead and any survivors they come across. The Rangdan were feared for their mimicry abilities, and their ships had a brutal appearance of spines and flails which dragged behind the vessels like metallic tentacles, giving them the appearance of jellyfish. Their elite warriors were said to be the match for a Space Marine in combat, wielding weaponry perhaps even superior to the Imperium and protected by personal energy shielding. Their preferred tactic was to use vast legions of slave armies and send them against the foe, exhausting them until selecting the right moment and place to strike. Their campaigns were conducted by Warmasters while their slave-controlling elite were known as Overlords.

Their warships fired radioactive electromagnetic blasts known as Shadow Blasters for the ominous shadow they left behind of their victims. They were capable of creating vast artificial war-moons manned by millions of slaves who were controlled via neural collars.


The Slaugth are known as “maggot men”, “dream eaters” and the “carrion lords” whose bodies and minds are completely alien to humanity. Their roughly humanoid form stands roughly as large as three meters in height. This body has hundreds of writhing maggot-like worms covered in a viscous, necrotic mucus. These traits allow them to stretch and reform their bodies at will whilst allowing them to move with on obscene boneless fluidity along with the capacity to regenerate at startling speed. Slaugth are impervious to age, disease, poison and are vulnerable to only the most extreme of injuries. Their alien minds are coldly savage and are psychic voids filled with a monstrous hunger for the dead. They are able to produce necrotic fluids from their body tissues, consisting of flesh-eating bacteria and molecular acids able to liquefy flesh or even burn through metal. The strange technology of the Slaugth combined with their unusual appearance has led many to mistakenly believe them to be daemonic beings. They are one of the xenos that conceal their true selves and walk amongst Mankind as if they were Humans themselves.

They are known to be an ageless and patient race with a psyche that is incomprehensible to the human mind though they do share one characteristic that others can understand – namely an addictive hunger. Above all other kinds, the Slaugth crave the dead flesh of other sentient beings, with a particular fetish for consuming cranial matter, which gives them a narcotic experience. Some say that this allows them to consume the memories and knowledge of their victims, and this theory is based in truth. Thus, while the Slaugth gain a more pleasurable narcotic experience from consuming rotting brain matter, they prefer to consume fresher brains for the purpose of gathering information. The memories gained from this process fade within weeks unless reinforced, repeatedily used or externally recorded.

Restraint is not considered a virtue within the racial hubris of the Slaugth, and so they do not see their obsessive hunger as interfering with their intellect. They are known to be extremely intelligent, highly resilient and – by human standards – completely evil

There are lots more mysterious Xenos races running around – which are your favorite and why?


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