“There is a cancer eating at the Imperium. With each decade it advances deeper, leaving drained, dead worlds in its wake. This horror, this abomination, has thought and purpose which functions on an unimaginable, galactic scale and all we can do is try to stop the swarms of bio-engineered monsters it unleashes upon us by instinct. We have given the horror a name to salve our fears; we call it the Tyranid race, but if it is aware of us at all it must know us only as Prey.”
— Inquisitor Bronislaw Czevak at the Conclave of Har
The Tyranids are a nasty insectoid xenos species from beyond the galaxy. They are essentially a space-faring ecosystem made up of countless diverse bioforms that are all variations on the same genetic theme.
The Tyranids are unlike any other intelligent species that Humanity has ever faced. They are the ultimate predators, and everything living, from the tiniest bug to the most advanced starfaring civilization, is prey to them. Only now are the residents of the galaxy recognising the gravity of the situation; if the Tyranids are not defeated, all life on the planet will perish.
In the end, the Tyranids species is only concerned with its own survival, propagation, and evolutionary advancement. The Tiranids are a monstrous superorganism that travels across the cosmos in their vast hive fleets of biomechanical Hive Ships, systematically destroying all other biomatter in order to allow for their own rapid evolution and reproduction.
The Tyranids have been compared to a galaxy swarm that consumes everything in its path, devouring entire worlds and leaving nothing but dead husks behind. The hive fleet’s menace is so great that an unprotected planet can be overrun and stripped of all biological substance in a handful of solar weeks without even slowing down the hive fleet’s approach.
All Tyranids organisms are “synaptic” (psychically reactive), and each Tyranids creature inside a hive fleet shares and contributes to a collective Hive Mind, which allows the Tyranid Hive Fleets’ billions of entities to communicate and organise on a massive scale.
The Tyranids philosophy of combat can be summarised by the statement “quantity has a quality all its own.” The signature of the Tyranids species, from the “lowly” Ripper to the deadly Hive Tyrant and beyond, is that they overwhelm their foes with sheer numbers, reproducing massive numbers of highly virulent organisms in record time from the biochemical soup derived from the biospheres of the worlds they consume.
When the Tyranid Hive Fleets clash with the Chaos daemons, neither race receives any help. The Tyranids have no sustenance from the inconstant Warp-stuff from which daemons are created, yet the unknowable entity of the Hive Mind is resistant to horror and daemonic corruption. As a result, these two super-predators fight for the chance to consume or despoil the galaxy’s huge stores of mortal flesh, tearing each other apart in a bloodbath from which only one can survive.
A Tyranids hive fleet’s components almost always move in huge groupings called as “swarms,” which are equipped with specialised biomechanical monsters capable of destroying and digesting a wide range of prey life forms.
The Tyranids have developed advanced ways for aiding cross-species DNA transfer. As a result, acquiring important new biological features from alien lifeforms is a major goal of any Tyranids invasion.
The Hive Mind uses them to improve the Tyranids’ ability to consume new worlds in order to obtain more organic raw materials for continued reproduction and guided evolution. A single, immensely intelligent female bioform known as a Norn-Queen reproduces all Tyranids.
The Norn-Queens of a hive fleet are the most important Tyranids in the fleet, because if they are hurt or killed, the Tyranids will be unable to reproduce from the seized bio-mass. As a result, Norn-Queens can only be found at the centre of the Tyranid Hive Ships that are the largest and most well-defended.
The Tyranids aren’t native to the galaxy; they’ve traversed the indescribable cold of the emptiness, where time and space combine to keep the stars separated by incomprehensible distances.
Nonetheless, the Tyranids bridged this chasm, travelling through the endless darkness for millennia to reach the galaxy’s edge.
Who knows what may lead an entire race to go on such an adventure? Perhaps the Tyranids have depleted their home galaxy’s resources and must hunt new feeding grounds or starve.
It’s possible that the Tyranids have been preying on galaxies since the beginning of time, and this is just the latest victim.
Some have theorised that the Tyranids are fleeing an even larger peril, such as a cosmic calamity or another terrifying alien threat, and have risked extinction by crossing the void between galaxies.
Whatever the case may be, the Tyranids’ ability to survive such a journey must have required inconceivable focus and energy. The Tyranids slept in a frozen form during their journey, but now that they’ve arrived, they’ve awoken, and they’re hungry.
The Tyranids originally appeared in the galaxy’s Eastern Fringes in 745.M41, according to the earliest recorded encounter between the Imperium and them. It is rumoured, however, that the Inquisition’s Ordo Xenos had spotted possible occurrences of this xenos species as early as the 35th Millennium.
The xenos emerged from the Local Group’s intergalactic space, their Hive Mind pulled to the Milky Way by the Astronomican’s mental beacon transmitted by the Emperor’s presence in the Warp from Terra.
The Imperium of Man’s first official contact with the Tyranids occurred during a Tyranids attack on an Ocean World named Tyran, and from there, Hive Fleet Behemoth went straight to the galaxy’s centre, devouring all worlds in its route.
During the Battle of Macragge, the Tyranids were vanquished by the Ultramarines Chapter of the Space Marines, although the Ultramarines sustained severe losses that would take decades to replenish.
Commissar Ciaphas Cain discovered hibernating Tyranids buried deep in the permafrost on the Ice World of Nusquam Fundumentibus in 942.M41 while on a mission; the swarm was apparently carried to the planet by a Hive Ship that had crashed on the planet seven millennia earlier, prior to any human colonisation.
The Hive Mind and members of the swarm were awakened as a result, although the swarm was finally defeated. The notion that the Tyranids had acquired a presence in the galaxy perhaps before the start of the Age of the Imperium, however, perplexed the Inquisition.
It’s unclear if the crashed bio-ship was on a scouting mission when it went missing, was a victim of an unknown adversary’s defeat of a pre-Imperial Tyranids invasion force, or was part of a Tyranids super-plot intelligence’s to “seed” the galaxy with many such slumbering broods.
The Tyranids returned to the galaxy in 993.M41 with Hive Fleet Kraken, which, rather than attacking its targets as a single massed Hive Fleet, divided into innumerable smaller fleets, each engulfing entire star systems before reinforcements arrived.
The Space Marine Chapters known as the Scythes of the Emperor and the Lamenters bore the brunt of this new offensive; the former was nearly totally decimated.
Though the hive fleet’s backbone was weakened by defeats at the Battle of Ichar and the Aeldari Craftworld Iyanden, the Imperium nevertheless paid a high price, as several splinter fleets broke away from the Kracken to wreak havoc deep within Imperial space, even reaching the Taow Empire’s borders.
Only a few Terran years later, in 997.M41, the Hive Fleet Leviathan came out of nowhere from “below” the galaxy’s plane and struck from two directions, cutting off major swaths of the galaxy from reinforcements.
The Tyranids were diverted into the star system of the formidable Ork Empire of Octarius in the Octarius Sector of the Segmentum Ultima, just when it appeared the Segmentum Solar’s and perhaps Terra’s defences would be put to the test.
While the Orks were able to halt the main Tyranids hive fleet’s assault in what has become known as the Octarian War, Leviathan tendrils had already begun to emerge victorious and stronger than ever after absorbing potent Orkoid genetic material into their own genetic pool.
The majority of Hive Fleet Leviathan moved to engulf Baal, the homeworld of the Blood Angels Chapter, in the dying days of the 41st Millennium. The Blood Angels summoned all of their Successor Chapters, with the majority of them sending forces to assist in the defence of their Primarch’s adopted home. However, the Leviathan fleet’s sheer magnitude threatened to overwhelm all of Sanguinius’ sons.
Warp Storms destroyed the Baal System as the Great Rift tore open reality, even as its worlds battled the Leviathan. The struggle between Blood Angels and Tyranids raged on Baal itself, but the massive Leviathan fleet orbiting Baal was torn apart by empyric storms and devoured by the Warp’s frenzy.
The moon of Baal Prime was invaded by Daemons, who annihilated a large chunk of the Leviathan’s invasion swarms. They were headed by Ka’Bandha, the Blood Angels’ ancient foe, who had determined that he and he alone would be responsible for the Blood Angels’ demise.
Before retreating back into the Warp, the Bloodthirster massacred the entire Tyranids host on Baal Prime and piled their heads high in the shape of his terrible symbol, leaving a chilling message for his hated opponents.
The main fleet of the revived Primarch Roboute Guilliman’s Indomitus Crusade landed at Baal as the Warp-spawned insanity of the Great Rift’s birth began to fade, supporting the few surviving Blood Angels in the eradication of the isolated Tyranids ground troops. Baal was spared during the Devastation of Baal campaign, but at the cost of nearly the entire Blood Angels Chapter.
The galaxy-wide cataclysm of the Great Rift tore a ragged tear across realspace in the latter days of the 41st Millennium, signalling the start of a new age of darkness, the Era Indomitus of the Age of the Imperium.
More Warp Storms followed, rippling across the galaxy and spewing ever-increasing amounts of Chaos’s raw matter into the material domain.
The Hive Mind may face tragedy as a result of the galaxy’s ongoing corruption. Tyranids hive fleets need a lot of biological stuff to power their cosmic attacks.
Chaos’ unstable, inconstant psychic energy gives none of this essential nourishment. With each passing season, the seething tide of empyric madness swallows over more planets and systems, depriving the Tyranids of the vital biomass that keeps them alive.
The Tyranids species, on the other hand, is characterised by its ability to adapt in the face of adversity. In the face of this threat, the Hive Mind’s timeless sentience has already evolved new organisms and hunting habits.
Following its defeat at Baal, the rest of Hive Fleet Leviathan launched a massive onslaught along the Segmentum Solar’s southern border.
Primarch Guilliman has dispatched scores of newly created Primaris Marine Chapters to the front lines of the Third Tyrannic War as the Leviathan pushes ever closer to Holy Terra.
Hormagaunts of the Tyranids are on the prowl.
The Tyranids are an extragalactic species that evolved beyond the void that divides the Local Group’s galaxies. Tyranids Hive Fleets travel through space utilising Hive Ships, which are giant animals genetically modified to traverse through vacuum and move in swarms
The Tyranids travel in vast fleets of enormous living animals that serve as spacecraft, each of which is home to many lesser Tyranids organisms growing in the vessel’s seething organ-sacs.
All of these animals were created to serve the Hive Ship as a single entity, and the ship itself only exists as part of the hive fleet.
Tyranids hive fleets typically migrate in ad hoc formations known as “tendrils,” eating all biological and organic material on a recently captured planet and breeding, often multiplying many times their original number.
When a hive fleet comes across a prey world, it does not invade for the sake of territorial gain, pride, or retribution. Indeed, it’s unlikely that the Tyranids Hive Mind comprehends such ideas.
Instead, they come to harvest precious biomass and satisfy their ravenous appetite. Not only do the Tyranids need an unlimited supply of food to feed their hive fleets, but they also need it to develop new organisms. When a hive fleet invades a planet rich in life, every Tyranids creature’s activity is geared toward a single goal: the entire and quick absorption of the planet’s organic people, ecosystems, and bioresources.
To this goal, the hive fleet assembles an army dedicated to defeating the prey world’s defenders before it is stripped of all biomatter and consumed.
Though they never reach the Warp, Hive fleets travel at superluminal speeds. Instead, they manipulate the gravity fields of star systems to enable faster-than-light travel by employing the specific psychic power of a Narvhal, a specially evolved Hive Ship.
The Tyranids Hive Mind’s vast Warp presence, on the other hand, manifests in that dimension through the Shadow in the Warp phenomena. Tyranids hive fleets have relocated to the Milky Way Galaxy, probably as a result of overpopulation or overfeeding in other nearby Local Group galaxies.
Given that each Tyranids hive fleet approached the Milky Way from a different direction, this could indicate that the Tyranids have devoured a huge number of surrounding galaxies.
The Tyranids are a space-borne species that has infiltrated Mankind’s and other xenos’ domains like a sickness spreading through an otherwise healthy body.
Tyranids hive fleets are made up of millions of biomechanical ships, each of which is home to a symbiotic life. In the spacecraft’ reproductive rooms, these creatures evolve and spawn from a variety of geno-organisms.
All of these beings were created to serve the ship, which exists solely to serve the Hive Fleet’s requirements. The Tyranids hive fleets are driven by the will of the Hive Mind, which is itself motivated by the most ineradicable instinct inherent to all lifeforms — reproduction, and through reproduction and the acquisition of new genetic traits, evolution to a better adapted form. Whereas other armies like the Imperium and the Taow fight for conquest or self-defense, and the forces of Chaos and the Ork tribes battle for the chance to wreak violence and havoc.
Even the most stalwart of humanity’s defenders are shocked, awed, and terrified by a fully mobilised Tyranids Hive Fleet. Even if the xenos danger is defeated (at a high cost), another Tyranids migration will develop soon to take advantage of the situation.
This is what makes the Tyranids species so dangerous: it’s an evolved meta-predator capable of out-producing, out-consuming, and out-lasting any other species it comes across, and it’s done it on an unfathomably large number of previous occasions throughout a broad expanse of cosmic space.
Each Tyranids hive fleet is classified by the Imperium’s Magos Biologis as a separate force, an unique entity that competes for resources with other hive fleets. Each appears to be self-sufficient, employing distinct techniques and creating unique creatures to thwart its target.
The fact, however, is more complicated, for each hive fleet is but a splinter of a larger assembly. Despite the Tyranids’ enormous numbers, swarms so big that they blot out the stars, each creature is merely a single cell in the living body of a single super-organism.
Every thought and action, every atom of life in the Tyranids species is united and intertwined into a single unfathomable awareness, a vast entity spanning hundreds of light years. The “Hive Mind” is the name given to this gestalt sentience.
It creates a psychic tie amongst all Tyranids, allowing them to act in perfect synchronisation. Since time immemorial, the Tyranids have fed on innumerable planets and eaten intelligent civilisations under the power of this ancient soul.
The majority of Tyranids species lack unique minds in the sense that they were developed to accomplish a particular purpose at the expense of everything else. Unless the Hive Mind’s inexorable will directs them otherwise, these organisms merely carry out the functions for which they were created, operating solely on instinct.
Tyranids bio forms that are larger and more complicated have been bred to make limited judgments in response to present stimuli and conditions, but even these acts are subordinate to the Hive Mind’s purposes.
The Hive Mind has the greatest impact in the proximity of Tyranids Warriors and the fearsome Hive Tyrants. These beings communicate with one another not through language, but by a synaptic sort of telepathy in which they relay and channel the Hive Mind’s will.
The Tyranids act in perfect synchronisation under the leadership of such beings, slaves to the psychic imperatives of a single communal brain. If these “synapse” species are killed, the link between individual creatures and the Hive Mind is lost, and many of the smaller organisms will revert to their animalistic behaviour.
As a result, Tyranids swarms have several commanders to ensure that the Hive Mind’s synaptic control is maintained over the Tyranids species as a whole.