The Yaotl

Slaugth lord.png This article describes a Xenos species in the /tg/ Heresy project, a fan re-working of the Warhammer 40k universe.
A Yaotl head
A Yaotl head

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The Yaotl are a dangerous xenos race of dubious sapience who have menaced human colonies near their section of the Halo zone since time immemorial. A particularly disturbing case of evolution run amok, it is only lack of warp capacity that holds the Yaotl back from overrunning nearby Imperial space and the innavigable nature of their own homeworlds which prevents the Imperium from exterminating these abominations in turn.

The Yaotl primarily inhabit the Halo Zone beyond the segmentums Pacificus and Tempestus, where they have built a sizable Empire. Lacking warp travel, the Yaotl instead utilize artificial wormholes forged in moon-sized industrial complexes. These must be towed at sub-light speeds to their destination, but once towed allow for near-instantaneous travel. The Halo Zone, however, is comprised primarily of small, cold stars and planets with low amounts of metals, and is thus incredibly poorly suited to the manufacture of such expensive constructs. To increase their living space, therefore, the Yaotl are forced to raid Imperial systems with sub-light armadas, stripping them of all available material and technology. The Yaotl have no interest in peaceful trade (it is the rare rogue trader who has the acumen to strike a deal with these repulsive beasts) and place no value in human life, even as slaves, and tend to treat humans as little more than a convenient source of volatile chemicals that need reprocessing before they can be used for industrial purposes.



Pre-Imperial ActivitiesEdit

The Darkness RimwardEdit

Angels and DemonsEdit



Yaotls are large, six-legged creatures bearing a superficial resemblance to certain species of Terran salamanders, although their biology is so freakishly divergent that none could suggest a link between them and Terran life. Yaotls are omnivorous and even slightly lithovorous, and possess sharp, bony plats in lieu of teeth capable of both shearing through and crushing their food. Yaotl demonstrate trilateral rather than bilateral symmetry, with the surplus limbs being located on the organism's back and providing it with high degrees of mobility in enclosed environments such as Yaotl structures or the subterranean warrens they call home. It is worth noting that non-cyborgized or otherwise modified Yaotl specimens are vanishingly rare, with each individual of the species apparently 'improving' themselves at every possible opportunity.

Yaotls are defined most by their bizarre system of reproduction. Yaotls are naturally hermaphroditic; each individual possesses the means to both produce eggs. Yaotl eggs, however, are fertilized by absorbing genetic material from around the egg; this means that the egg must be implanted in another Yaotl to be fertilized. Since Yaotl pregnancy results in several young Yaotl chewing their way out of the unfortunate parent, a Yaotl will not willingly mate outside of their defined mating season, when hormones force them into a state of insatiable lust. Matings resemble duels, with both partners attempting to impregnate the other Yaotl without themselves becoming impregnated; the dominant partner successfully reproduces, while the beta pays the intense physical cost of 'childbirth'. While in previous generations 'childbirth' was almost always fatal, at some point in the past the Yaot race was genetically engineered on a large scale; now most survive their pregnancies, causing rapid population growth.

Immature Yaotl or Yaotl who have recently been impregnated are driven by hormones into slavish devotion to their Alpha, forming a natural clan structure in the species. Yaotl are naturally highly territorial, and clans do not tolerate individuals not bound to their Alpha except during mating season. Upon maturity, the young Yaotls wander off into the ill-defined borders between clan territories and attempt to survive until they can mate, start their own clan, and claim territory for their own. The need to acquire new territory and avoid large-scale social conflict, fed by this instinctual behavior, has been one of the driving forces behind Yaotl expansion.

The most alarming trait the Yaotls incorporate into their bizarre biology, however, is the rise in intelligence in a dominant Yaotl following a successful mating. Still poorly understood by Imperial scientists, after a Yaotl implants another with its eggs its neuron density begins to increase rapidly; over a period of several Terran months, the Yaotl in question will have gained roughly 10% more neurons than it previously had. No limit to this growth has yet been discovered, although as the brain grows to the extent that the body cannot support it the individual Yaotl often upgrades itself to compensate with cybernetic or genetic enhancement. Whether or not this trait was engineered into the Yaotls is unknown and highly debated among the Ordo Xenos. Yaotl do not possess brains in the manner that most Terran life does, instead distributing their intelligence via a neural mesh throughout their entire bodies. It's fiercely debated among the Explorators and Ordo Xenos as to whether or not Yaotl individuals, in the human sense, exist at all or whether 'individual' Yaotl are more akin to biological process mimicking sentience. Lack of psychic ability or any presence in the warp at all seems to support the latter theory - the Yaotl are, by any definition of the word, soulless.

How evolution produced such a hideous species is hotly debated among the Magos Biologis. Some have gone so far as to assert that such a development is not, in fact, possible via natural processes. Should this prove true, whichever race engineered the Yaotl, and for what end, are unknown.


While the Yaotl are clearly organized and capable of cooperating on projects of massive scale, it is debatable as to whether or not they have a society at all. Yaotls do not naturally socialize as humans do, as they do not negotiate for mating rights and are too territorial to interact with anyone other than their hormonally indoctrinated young, and have only been witnessed communicating with one another through machine interfaces. Aside from binary communications between Yaotl-built systems, which Mechanicus Explorators have confirmed do not imply an overarching language even on a single colony or even a ship, no Yaotl has ever been observed to communicate in a language other than that of the rare individual they have elected to approach for trade.

Yaotl are organized by their biology into clans, consisting of a dominant individual, their immature servants, and other Yaotls that have either been recently impregnated by the Alpha or are recovering from the birthing process. Between the territories of these clans lists an ill-defined neutral zone, where mature Yaotls who have not yet mated (or have mated, but as the inferior partner) languish, awaiting the opportunity to seize their own territory and start their own clan. This would be the highest state of Yaotl 'civilization' were it not for Yaotl biology naturally producing individuals whose intelligence vastly exceeds that of the average or even exceptional human. These individuals can effectively manipulate less intelligent Yaotl alphas, allowing for clans to form larger political structures (frequently, without the knowledge of those inside the clan itself). This arrangement is more akin to one (or more rarely, a few individuals) training and cajoling animals than it is a society or organization, as Yaotl vary in intelligence from sub to (heretical as it may be to make public) considerably above human levels. Thus, the Yaotls have a complex and ever shifting web of alliances, tributary clans and manipulated clans. Yaotl politics is to shadowy, complicated and chaotic for most races to grasp; fortunately for diplomats but less fortunately for neighbors, the Yaotl do not seem to be interested in dealing with outsiders in a non-violent fashion apart from the extremely rare trade. The primary activity of these clan networks, generally referred to among the Ordo Xenos as Tyrannies, appears to be the subjugation of rival Tyrannies, strip-mining their territory of all available resources, and occasionally organizing large scale raids which can devastate entire sectors.

The Yaotl Hierarchy, as the Imperium has designated it, is the main Yaotl polity. This is the largest and oldest stable Yaotl entity known to date, and raids the Imperium with much less frequency than other, shorter-lived Yaotl tyrannies, while having conducted more than half of known trades between Yaotl individuals and other species. The Hierarchy found in the Halo Zone near the border of the Segmentums Pacificus and Tempestus; smaller Yaotl empires can be found in the surrounding regions, or rarely further into Imperial space. Due to the nature of the Halo Zone, there is little contact between the Hierarchy and the Imperium beyond periodic raiding fleets and the rare Imperial reprisal when the opportunity presents itself. How the Hierarchy itself is structured is unknown, but speculated to be radically different from the petty tyrannies surrounding it. Though knowledge of the astrography of the Halo Zone is hazy, it appears that over the centuries the Hierarchy has been drifting ever closer to the Segmentum Tempestus for unknown reasons.


The Mechanicus regards Yaotl technology as, like the Yaotl themselves, particularly unholy even in comparison to other xenos. While other races may concoct blasphemous technologies in their own right, Yaotl technology seems particularly close to the technology of man, twisted by alien minds towards a dark parody of the Omnissiah's teachings. Radical Magos who preach that studying the tech-abominations of the alien only serves to further knowledge of human technology through contrast form the vast bulk of Mechanicus who have dealt with Yaotl technology beyond destroying it, and among these near-heretekal communities the Yaotl are regarded as a particularly useful point of comparison. The Yaotl are widely held to not, unlike most other species, actually know in the sense that humans do at all, but rather to through some analogous process behave as though they do. This discovery can be traced back to Archmagos 10011010011101, who managed to partially decipher historical records predating the Age of Strife which posited that the Yaotl were an example of the ancient theory of a 'Synys Rom', a kind of theoretical machine-spirit that could carry out conversation to the point that it could be mistaken for a human but without at any point understanding the meaning of its own words.

Yaotl technology in many aspects seems to operate via that same fundamental mechanisms as human tech and archeotech, but it is readily apparent to a learned observer where the xenos devices differ. Yaotl mechanics are immensely more efficient in terms of space and overall mass and power consumption, but whereas in human technology this is a result of refinement of form among the Yaotl this is the result of extremely chaotic conflict of multiple contradictory devices. Some aspects of their technology are completely inexplciable; energy appears are if from nowhere, components move in the opposite direction force should direct them to and stability emerges from chaos.

The Yaotl are seemingly quite advanced in the manipulation of their own bodies, implanting biological or mechanical systems with the same casualness a Terran changes clothes. It is often difficult to tell where the organism ends and the machine begins. The Yaotl also infrequently display sweeping changes in their genome, usually during periods of high resource scarcity, that is undoubtedly artificial in origin; the high level of internal competition among the Yaotl however seems to have prevented any subspecies from diverging too far from the average Yaotl's genome. The Yaotl are also highly skilled in deceiving the senses and disrupting cogitators. In the presence of Yaotl raid fleets friends are mistaken for foes, enemies appear seemingly from nowhere, visions of targets are revealed to be illusions and machine spirits lash out in violent, random spasms. Against this nightmarish sensory assault, Imperial forces rely on superior numbers and coordination; should one or the other advantage be negated, defeat becomes unstintingly likely. Yaotl weaponry is a mix of crude and refined technologies. Most commonly employed are magnetically-propelled darts of small size but high mass, piston-propelled piercing or blunt weaponry, bolts of sheer electrical charge or streams of particles that erode flesh, ceramite or void-shield with equal ease. Yaotl doctrine generally emphasizes infrequent crushing blows, delivered in large numbers from an unexpected direction. Magnetics in particular are a superficiality of Yaotl engineering; their ships primarily propel themselves through anomalous mono-directional magnetism or by magnetically bottling and expelling inert gas. The most remarkable abomination of Yaotl tech, however, is their interstellar drives. Though lacking in knowledge of the Warp the Yaotl seem to have devised an esoteric method through which two points in space can be joined and a passage burrowed between the two. Moving one of these 'gates' at sub-light speeds, the Yaotl gain near instantaneous access from one end of the gate to another. Manufacturing these gates requires absurd amounts of energy, and takes place in cyclopean industrial complexes the size of small moons - how the Yaotl manage to coordinate to the degree necessary to construct such immense structures remains fiercly debated amongst the Ordo Xenos, with many believing that some other race must be responsible. If true, the implications of this alliance - that the Yaotl are mere pawns or even weapons of another, hidden threat - are chilling.

Thankfully, the Yaotl appear to be relatively stagnant in terms of technological development; what historical records we have show that, at least since the mid Age of Strife, their capabilities are fundamentally unchanged. This is most likely due to the unsocial nature of the Yaotl resulting in all discoveries made dying with their creator, only to be recreated by the next alpha to attain sufficient intelligence to recreate their predecessors progress.

Forces of the YaotlEdit

Naval ForcesEdit

Type I: Nestship: The only Yaotl ship observed to rival an Imperial cruiser in size, although like all Yaotl ships it is crewed by a single clan. Nestships are the only Yaotl ships to travel between the stars at sublight speeds, and are built around a central wormhole. The true lynchpins of a Yaotl raiding fleet, Nestships attempt to avoid combat and will scuttle themselves to avoid being captured if necessary; however, it is more likely that a raiding fleet will fight to the death to protect its Nestship, as it represents a huge investment in resources and their only method to return to Yaotl space. Nestships carry large amounts of Drakes, and bristle with automated point defense systems. Paradoxically, they are also more stealthy than smaller Yaotl ships, capable of disrupting an entire system's worth of sensors.

Type II: Corsair: The main capital ship in Yaotl fleets, roughly equivalent in size to an Imperial frigate. Corsairs are built around a central multi-pronged drive system that allows for extreme maneuverability compared to Imperial ships. Their small size, however, means that they are fairly fragile, something only compounded by the Yaotls lack of void shielding. Instead the Corsair relies on highly accurate automated point defenses and a vast array of electronic warfare devices. When operating in concert, a pack of Corsairs is all but untargetable, as sensor ghosts overwhelm Imperial cognitors and visual targeting is rendered useless by flashy diversions. Corsairs typically operate in Swarms, as their defenses are more potent when used in concert; in addition, though they punch above their weight compared to Imperial ships, concerted firepower remains necessary for Yaotl fleets to defeat larger vessels.

Type III: Drake: At first, the Drake was thought to be a Yaotl interceptor. Recovered wreckage however has revealed that Drakes are in fact highly modified Yaotl, the individual organism being lost in a sea of cybernetic implements. Drakes typically cling to other Yaotl vessels, exposed to the vacuum, until they are within range of an enemy vessel. Drakes rely largely on their stealth to avoid destruction, acting in concert with other vessels to bring down much larger ships. Drakes are quite superior to Imperial interceptors in a dogfight, although should they loose the element of surprise of face overpowering numbers their fragility means they will crumble quickly.

Making Imperial Navy response to raids difficult is that no two Yaotl ships are exactly alike, each being designed personally by an abnormally powerful Alpha and in many cases in service for centuries if not millenia due to the immensity of the investment required to build a single vessel, resulting in perpetual modifications and an ever-increasing functional disorder. In the rare advent that Yaotl ships are taken intact, the alien workings of their minds is revealed in the nature of the ships layout, a sprawling mass of unfathomable passages and subsystems, many of which are seemingly non-functional but when brought offline having an unpredictable effect. More than one Imperial boarding team has been wiped out by putting a slug in a seemingly aesthetic wall decoration that turned out to, when damaged, cause the local atmosphere to be increased in pressure tenfold, or other such esoteric consequences. Many remark that Yaotl vessels are more akin to space hulks than true starships, but the uncanny functionality these ships demonstrate when in the hands of a Yaotl alpha belies this.

Ground ForcesEdit

The Yaotl do not appear to coordinate in engagements at all beyond the level of an alpha herding its thralls towards the enemy and watching the ensuing carnage unfold. Yaotl do not seem, other than thralls of an alpha fighting in the same general area, to utilize unit-based tactics at all. Yaotl warriors seldom appear to have uniform equipment, body modifications or even to employ a coherent approach to warfare. Their seeming lack of socialization in human terms, however, may simply mean that their means of coordination are simply incomprehensible to the human mind. Mechanicus observers have remarked that Yaotl Riotswarms demonstrate coordination in response to threats faced by Yaotl forces of an entirely different alpha, sometimes located hundreds of kilometers away. Whatever the nature of this response, it is notably slower than that of more conventional species. If not for the unpredictability and chaotic nature of Yaotl assaults, Yaotl ground forces would be easy prey to a resolute and coordinated foe. As it is, the rare advent of Yaotl infantry being encountered outside boarding actions or invasion of a world already nearly bombarded into submission from orbit, they have tended to lose engagements with the Imperial Army.

No two Yaotl warriors are alike. Some have modified their body to the point that they can be easily mistaken for an armored vehicle while others are stripped of all unnecessary tissue and implants and race into enemy lines unarmed at breakneck speed. One common aspect of Yaotl warfare, however, is its heavy reliance on deception; most Yaotl warriors will deliberately disorient victims using a wide variety of technologies and tactics. Against Imperial forces with poor morale or discipline, this generally results in the battlefield degenerating into anarchy as chains of command cease to bind individual soldiers. The Yaotl Riotswarms have two primary weaknesses; the first is a resolute and coordinate foe, who can systematically engage in area denial until Yaotl warriors are forced into ever increasing pockets and eliminated, or through targeting the Alpha of the Riotswarm, easily distinguishable by its self-preserving behavior in contrast to the unpredictable and sometimes suicidal behavior of its thralls.

Xenos of the /tg/ Heresy
Orks Da Merc - Kaptain Blackjawzz - Khork
WAAAGH! Mongo Mork - WAAAGH! Sarkus
Eldar Craftworld Eldar - Harakien Empire
Webway Lords & Dark Eldar
Compact of Free
Galactic Interchange
Ellonoi - Metabasil - Slaugth - Tau - Vespid
Other Dangerous Aliens Anatik - Cyfecti - Morkai - Strixoros - Yaotl