The Tyranids, also known as The Great Devourer are an extragalactic alien race, whose sole purpose is the consumption of all forms of genetic and biological material in order to evolve and reproduce. Tyranid technology is based entirely on biological engineering. Every function is carried out by living, engineered creatures, each of which collectively forms the Hive Fleet, directed by a single Hive Mind.
The Tyranids are seen as one of the gravest threats to the entire Galaxy. They seek only to consume all organic life and cannot be reasoned with or deterred in this quest. Worse still for the Galaxy, thus far the Tyranid Hive Fleets that have been encountered are merely the furthest stretched tendril of the main invasion fleet that is still traveling in the void of space.
The exact origin of the Tyranids themselves is unclear, save the fact that they are not of The Galaxy and have only recently arrived here after traveling countless millennia in the intergalactic void. It is unknown which galaxy they originated from, or for how long the Tyranid race has been on its genocidal rampage, but it is believed that it is the Astronomican that is drawing the Tyranid Hive Fleet to threaten the galaxy[1j]. The Tyranids were first attracted to the Milky Way Galaxy when the xenos communication device known as the Pharos was overloaded in the Battle of Sotha during the Horus Heresy. Indeed their very name is but a title given to them by the Imperium, named after the planet where they were first encountered (Tyran). It is possible that they have been preying on other galaxies since time immemorial.[1b] According to another source, they have consumed one thousand galaxies and are responsible for the annihilation of millions of intelligent species.
The Imperium's first official contact with the Tyranid race was in 741.M41, when the Hive Fleet later known as Behemoth invaded the Eastern Fringe and annihilated planet Tyran. However, reexamination of Imperial records has led to speculation that the Tyranids have been invading, or at least probing, the Galaxy for much longer. Some of the Galaxy's most notorious predatory beasts, such as the Catachan Devil[2b] or the Fenrisian Kraken, are guessed to be the descendants of ancient Hive Fleets. Records kept by the Ordo Xenos of the Inquisition suggest contact with Tyranid bio-forms as early back as M35; even more remarkable, in 937.M41, a Bio-ship was discovered beneath the surface of Nusquam Fundumentibus, where it had lain dormant since around M34. This discovery raised the disquieting possibility that other dormant Hive units are already "salted" around the Imperium as a whole, waiting for a new Hive Fleet to awaken them.
Hive Fleet Behemoth was largely defeated at the Battle of Macragge in 745.M41[1d]. However this was hardly the end of the Tyranid menace. After Behemoth, the next major Hive Fleet to move into the Galaxy was Kraken in 992.M41, though tendrils of this Hive Fleet were defeated by the Imperium Ichar IV Campaign and by the Eldar at the Battle of Iyanden.[1j]. Despite these setbacks, the Tyranids continued to advance into the Galaxy through a variety of smaller Hive Fleets. In 997.M41 the largest Tyranid Hive Fleet encountered so far, Leviathan, moved into the galaxy below the galactic plain.[1l] However thanks to the formation of the Great Rift, much of Leviathan was cutoff as it made its main assault on Baal, homeworld of the Blood Angels. Most of Leviathan was destroyed during the period known as the Blackness against the defenders of Baal, the Indomitus Crusade, and newly materialized Daemonic armies. However the Hive Fleet still has many tendrils remaining, which are now surging towards Segmentum Solar.
An Imperial research body dubbed the Strategic Collective has determined that the Tyranid Fleets encountered so far are just the initial reconnaissance units for a far greater whole. Their report advised the Departmento Munitorum to increase mobilization and recruitment by a minimum of 500%. Such a number, if attempted, would mean the conscription of every man, woman, and child on every world of the Segmentums Solar, Obscurus, and Tempestus.
Some most of the major Hive Fleets include:
- Hive Fleet Ouroboros - M36[1f]
- Hive Fleet Behemoth - 741.M41 (the Imperium's first official contact with the Tyranid species)[1c]
- Hive Fleet Naga - 801.M41[1e]
- Hive Fleet Gorgon - 899.M41[1f]
- Hive Fleet Kraken - 993.M41[1g]
- Hive Fleet Jormungandr - 995.M41[1h]
- Hive Fleet Leviathan - 997.M41[1i]
- Hive Fleet Hydra - M41[1k]
- Hive Fleet Kronos - M42
The Tyranid forces are constantly changing and evolving at an unnatural speed. It is unlikely that all types of Tyranids have been seen by the Imperium, and still less likely that they will ever all be seen. However a few key traits are identical to nearly all Tyranids, such as tough chitinous armor, a hexapedal anatomy, and multiple redundant organs which make them incredibly difficult to kill.[15a]
Every weapon and projectile used by the hive fleets is a living organism, grown from the reconstituted biomatter of previous invasions. The Tyranids have no form of mechanical technology and, instead, harness an advanced form of biotechnology. These creatures live in a highly symbiotic fashion, fusing into each other’s flesh so that it is often impossible to say where one Tyranid creature ends, and another begins. This relationship is most obvious in the larger constructs, whose repurposed anatomies still retain recognizable biological shapes. However this "forced parasitism" exists at every level, with examples such as "thinking blood", organs that can live separately from the creature they served, and subsidiary brains that serve as a "backup" in case of primary brain death or contain some specialist knowledge necessary for the current invasion. In this way, Tyranid warrior-beasts wield living weapons that are literally extensions of their own bodies, each one a killing machine, perfectly adapted to slaughter its victims. In addition, Tyranids are highly toxic to all forms of life, and many of their organisms expel toxic spores during invasions to make a world uninhabitable to non-Tyranid life.[14b]
The bio-construct nature of the Tyranids makes them a terrible foe to face, for their armies contain a creature specialized for every conceivable facet of warfare, which can be altered and regrown to suit a battle’s needs in a short span of time. Thus can a hive fleet adapt to generate a force capable of overwhelming any opposition, unleashing a vast throng of ferocious alien monsters that can fly, run, burrow and stalk through the defenses of any foe.[14b]
The Tyranids do not communicate with the other races of the galaxy. The Tyranids cannot be reasoned with, appeased or surrendered to. There can be no hope of mercy from such a foe. To face the Tyranids is simply a matter of survival: kill or be consumed.[14b]
The raw matter of Chaos offers no nourishment to Tyranids, and this is why the Hive Fleets normally avoid areas plagued by Warp Storms and Daemonic activity. This has become more difficult, as the impure essence of the Warp increasingly pours from the Great Rift and across the galaxy. This has caused vital resources to be denied to the Hive Fleets and Kronos appears to be the Hive Mind's solution to this problem.
The Tyranid swarm is endless and constantly evolving, and in any given Hive Fleet there are an endless variety of creatures that have been incorporated into the Swarm.[15c] However a few key organisms are consistently observed in Hive Fleets. The most frequently encountered Tyranid species are the:[14c]
- Leadership Organisms[14c]
- Specialist Organisms[14c]
- Basic Organisms[14c]
- Heavy Organisms[14c]
- Super-Heavy Organisms
- Flying Organisms[14c]
Originally creatures called Zoats were part of the Tyranid force and some Magos Biologis believe that they are left over from a much earlier Tyranid invasion, although they appear to have disappeared from common sight[Needs Citation].
The Hive Mind
Within the Tyranid swarm there is no idea of individualism as each unit is linked to the next in a form of swarm consciousness. There is only one reason for the creation of any of the forces involved in Tyranid armies: to implement the will of the swarm, be it a Hive Tyrant or Ripper Swarm. This gestalt consciousness is commonly referred to as the Hive Mind.
Certain Tyranid units are considered Synapse Creatures, whose job it is to control the lesser species within the swarm and exert the will of the Hive Mind. They are capable of receiving and sending orders via the Hive Mind and this connection is vital to the effective running of the Tyranid race for, without it, the swarm would collapse into disarray. Usually Synapse Creatures are fielded in relatively large numbers to allow a rapid advance of the lesser creatures to remain in range of a synapse creature.
The Tyranids seem able to achieve Faster-than-light travel through an organism known as a Narvhal, which is able to harness a targeted systems gravity and propel its accompanying Hive Fleet's Bio-Ships to its destination. The arrival of the Tyranids is often met by psychic disturbances dubbed the Shadow in the Warp.[14b]
In the process of assimilating a planet's biological and inorganic materials, the most important stage is the location of a suitable target. One method by which they accomplish this is the spectral analysis of distant stars to determine their likelihood of supporting life. However, the fastest and most common method is the use of vanguard organisms, millions of which range hundreds of light-years ahead of each Hive Fleet, investigating each star system they encounter for signs of life. Once a suitable world has been detected, these bio-vessels spawn infiltrator-organisms, such as Lictors, Genestealers, or specialized Gaunt strains, and launch them onto the world via Mycetic Spores. Once inserted, these organisms will seek out all life and target those of a highly-organized nature, such as humans, restricting themselves to lone targets so as to avoid revealing their presence. Genestealers in particular will seek to infiltrate communities and create cults, not only to signal the planet is ripe for consumption but to weaken its defenses against the Hive Fleet's arrival.
As the psychic beacon of the infiltrator-organisms flourishes, indicating a rich feeding ground, so does the Hive Fleet home in on it, in the process cutting off all interstellar communications as the Shadow in the Warp blankets the target system. Upon arrival to the planet, the Hive Fleet will disperse within the planet's upper atmosphere and begin launching millions upon millions of Mycetic Spores. Many will contain Tyranid warriors of various strains, from Rippers to Bio-Titans, and so come in a multitude of sizes. Others will deliver zoomorphic symbiotes and parasites, which target and mutate the planet's flora at a rapid rate. Within hours verdant forests are replaced with highly-aggressive alien vegetation, including Capillary Towers, which begins the process of transforming the planet's atmosphere into a hothouse, turning the sky a sickly red and raising temperatures at an accelerating rate. Other spores are nothing more than giant cyst-bombs, filled with viral and poisonous organisms which burst over population centers, killing millions of people in the opening hours of the attack. Each one will cover an area many hundreds of meters across with acidic digestive bile, starting the process of future ingestion.
After the initial attack, vast swarms of flying Gargoyles will herd the native population into the path of fast-moving hordes of Gaunts to be viciously slaughtered. The defenders, often underestimating the Tyranids' intelligence, make fighting retreats to buy themselves time to regroup from the onslaught, only to be encircled and destroyed as it becomes apparent they were merely herded into prepared killing grounds. These last pockets of resistance will become the targets of larger Tyranid species, from Warriors to Carnifexes and Bio-Titans, which eradicate the defenders with sheer offensive power.
With resistance ended, consumption of the planet's resources begins. Bacterial agents and vast tracts of feeder organisms, pupated from the carcasses of native life forms, ravage the landscape of every ounce of biological matter before being collected into Reclamation Pools, where the matter is rendered into a thick, nutrient-rich gruel. This includes all mutated plant-life, which has finished altering the atmosphere into an oxygen-rich environment, and any infested organisms, who march blank-faced into pools' depths to be consumed by the Hive Fleet. As the digestion pools swell, the Hive Fleet's ships cluster in low orbit as vast capillary towers emerge to link with proboscis-like feeding tubes and pump the biomass into them. The final stage of the harvest is the consumption of the world's atmosphere and seas, with vast drone-ship haulers descending to low orbit and sucking up every useful element left. Eventually the Hive Fleet will depart, having left the world a desolate airless rock stripped down to the molecular level, to begin the consumption process on another world. The Tyranids will also consume metal, rocks, and other minerals for microscopic life, but usually can not obtain much biomass from this.
|00||Initial mycetic spores are dropped, generally containing Lictors or Genestealers. Infiltration force led by a synapse creature of some kind; reproduction of Tyranid creatures likely begins immediately.|
|09||By day 9, Tyranids will have expanded to around 200 km from the drop point, and will likely present a significant threat to planetary defence and resident Imperial Guard forces.|
|13||Tyranids will have expanded to 700 km from the drop point; may begin infesting local water sources.|
|37||Tyranids control area within 2000 km radius of the drop point; basolithic infestation to 5000 km radius.|
|48||Tyranid population growth skyrockets, with population doubling approximately every 2.5 days.|
|50||Main Hive Fleet arrives, craft generally numbering around 1.5 billion. Psychic contact with planet is cut off by the shadow of the Hive Mind. Any attempts to escape are quickly stopped by the Hive Fleet.|
|51||Primary consumption of bio-mass begins (resistance has generally been eliminated by day 51). Brood ships land, releasing Ripper swarms, which consume all remaining organic material and depositing them at the reclamation pools. Capillary Towers (and the Brood ships) send the material into orbit.|
|80||The hive ships descend into the upper atmosphere and begin collecting it. Reduction in atmospheric pressure causes oceans to boil away, which are also collected. Lack of oceans causes plate tectonic shifts, dramatically increasing volcanic activity. Upon completion, the Hive Fleet move out of the system in search of fresh prey.|
|100||The Imperial Navy arrives in response to the distress call to find the world lifeless.|
According to Belisarius Cawl, the Tyranid consumption of a planet is only surface-deep. Water and microbes continue to live on deep below its surface. Thus with the right terraforming technology and time, it is possible for worlds consumed by the Tyranids to return to life.
Though the Tyranids are wholly controlled by the Hive Mind and lack any sense of individuality[1b], a number of individual organisms have been repeatedly encountered by the Imperium and others within the Galaxy. These genetic abnormalities have gone on to earn dreadful reputations for themselves.[1m]
Notable individual Tyranids include:[1m]
- The Swarmlord - Legendary Hive Tyrant who is the pinnacle of the Tyranid race.
- Old One Eye - Carnifex
- The Doom of Malan'tai - uniquely adapted Zoanthrope
- Deathleaper - Lictor
- Parasite of Mortrex - Winged organism
- Red Terror - Ravener[1g]
- 1: Codex: Tyranids (5th Edition)
- 2: Codex: Tyranids (4th Edition)
- 3: White Dwarf 145 (UK), pgs 36-37
- 4: White Dwarf 305 (US), pg. 80
- 5: White Dwarf 306 (US), pg. 67
- 6: White Dwarf 307 (US), pg. 98
- 7: Tyranid Art
- 8: Codex: Space Wolves (5th Edition), pg. 63
- 9: The Last Ditch (Novel), Chapter Twenty-Nine
- 10: Warhammer 40,000 6th Edition Rulebook, pg. 215
- 11: Warhammer 40,000 5th Edition Rulebook, pg. 166
- 12: Pharos (Novel), Epilogue
- 13: Belisarius Cawl: The Great Work (Novel), Chapter 5
- 14: Codex: Tyranids (8th Edition) pg.37
- 15: The Devastation of Baal (Novel)
- 16: Warhammer 40,000 8th Edition Rulebook, pg. 52
- 17: Codex: Tyranids (8th Edition) (E-Book) — The Third Tyrannic War
- 18: Codex: Tyranids (3rd Edition) - The Stark Report
- 19: Imperial Armour Volume Four - The Anphelion Project, pgs. 80-94
- 20: Forgeworld Tyranid Dimachaeron (archived 4/3/2021) (last accessed 4/3/2021)
- 21: Battlefleet Gothic: Armada II - Tyranid Fleet List
- White Dwarf 255 (UK), pgs. 30, 49 (1)