Tyranids

Tyranids form a superorganism: they travel the universe on their Hive Fleets, destroying all ecologies in their path. They are psychically linked via their Hive Mind, which gives them great abilities to strategize and coordinate. When one Tyranid sees something, within an instant the entire Tyranid race is aware of it.

The mentality behind the Tyranid race can be summed up by the phrase "quantity has a quality all its own". From the lowliest Ripper swarm, to the deadliest Hive Tyrant, the signature trademark of Tyranids is that they swarm over their foes, obliterating everything before them without regard for species or race, seeing all life as merely fresh meat; new gene code to be assimilated, processed, and cycled into the spawning cycle to generate deadlier species off-shoots.

Tyranids were first described in the first edition of Warhammer 40,000 (Rogue Trader), with their basic form not too different from today. Their only additional troop type was an enslaved race, the Zoat. At that time they were not an emphasised race in the 40K universe (see External Links). In later editions they became a playable race in their own right, and it was revealed that the Genestealers (popularised in Space Hulk) were in fact part of and the advance force for the Tyranid army.

Description
The Tyranids are actually an extragalactic race of evolving creatures. Traveling in vast hive fleets in the voids of space, they are likened to galactic locust swarms, to powerful to stop and to fast to deal with. They migrated from other galaxies in search of more resources of bio-mass to consume, as their hive fleets 'devour' entire planets at a daily basis.

Their hive fleets consist of millions of living crafts, each serving as the home of untold numbers of tyranids. These monstrosities evolve from bubbling geno-organisms in the ships' reproductive chambers. All these creatures are born to serve to a single entity, that is the ship, and the ship in turn exist only to serve the hive fleet.

The Organism
All tyranids are held in a common psychic bond. This bond enables the forces of Tyranid to think, perceive and act as a great whole, allowing complete command over its constituent parts.

From the smallest feeder organisms to the huge tendril-like shoals of the hive fleets, every Tyranid is bound to the will of the Hive Mind. The lesser and smaller creatures are mindless and instinctive, while larger more complex creatures can make decisions appropriate to the situation.

Psychic Web
They function on perfect unison, coordinated by powerful psychic imperatives transmitted by a communal sentience. Their fleets, hordes and broods do not have a single commander, instead, a synaptic web of psychic influence controls them.

For this reason, should the influence of the larger Tyranid organism be removed, the lesser creatures will revert to animalistic behavior.

The creatures that channel the commands of the Hive Mind are mostly, if not all, potent psykers. They communicate with their brethren not by language, but a kind of instinctive telepathy. How this is done without drawing clouds of the daemons of Chaos into the material universe is a mystery. Some say that the absence of souls in them prevents this from happening.

Growing War Machines
The Tyranids do not build their starships and weapons from metal and plastic, instead, they use gene-splicing and bioengineering to grow them form the living organic material harvested from the planets they consumed.

Every weapon, gland and projectile used in their armies is a Tyranid organism in its own right, from the spores polluting the atmosphere, to the grotesque spires that burst from the tortured ground during an invasion.

Tyranid Battle Tactics
Tyranids often attempt to first take a planet through infiltration. Space Hulks and other derelict spacecraft are infested with Genestealers, which quickly familiarize themselves with the layout of their new home, then hibernate.

When the Hulk is eventually discovered, the Genestealers attack the exploration crew, sometimes killing some crewmembers, but always leaving at least one survivor who is implanted with a seed, similar to a Xenomorph Facehugger.

Unlike the facehugger, this infestation is never fatal, but instead subtly alters the victims DNA, giving them a strong urge to mate. The child that results from this union will be a Genestealer hybrid, which now has the complete loyalty of its parents. The Hybrids continue to breed and multiply among the population, eventually forming a Genestealer Cult. As the Cult grows in numbers, it begins to spread its influence throught the planet, placing its members in positions of power within the government and the military. At the same time, it begins to emit a psychic signal through the warp that acts as a beacon for the Hive Fleet.

As the fleet nears the doomed world, the cult goes into action, instigating a worldwide rebellion with the goal of weakening the planet's defenses against the approaching Hive Fleet. The Hive Fleet will also seed the planet with Tyranid organisms, which will begin to alter the planet's surface and ecosystem to make it easier to consume.

If the Hive Fleet is victorious, the fleet will descend to the planet, inhaling the atmosphere, drinking the seas, and basically consuming its nutrients until nothing more than a lifeless ball of rock remains.

On the battlefield, Tyranid tactics are based around the notion of superior numbers (try to outnumber the enemy three to one). Tyranids overrun opposition in close combat, closing faster than most armies. They possess few ranged weapons, but their sheer numbers and close combat specialization makes up for the slaughter if they are commanded by a worthy commander.

Stages of the Planetary Devour
Generally, contact with the Tyranids occurs when a Hive Fleet invades a system for the purpose of harvesting its bio-mass. A Hive Fleet contains an enormous number of Tyranids, and they are brought to bear against resistance in the most efficient manner possible. Below is a general outline of a typical Tyranid planetary assault (in particular, this data is collected from the Tyranid invasion of Dalki-Prime):


 * Day 00: Mycetic sporess are dropped, mostly containing Lictors and Genestealers. As soon as they hit the ground, reproduction of Tyranid creatures likely begins immediately.
 * Day 09: By now, Tyranids will have expanded to around 200 km around the drop point, and will likely present a significant threat to PDF troopers and resident Imperial Guard.
 * Day 13: Tyranids have expanded to 700 km from the drop point; some may begin infesting local water sources.
 * Day 37: Tyranids completely control the area within 2000 km radius of the drop point and basolithic infestation begun to reach to 5000 km radius.
 * Day 48: Tyranid population growth skyrockets, with population doubling approximately every 3 days.
 * Day 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.
 * Day 51: Primary consumption of bio-mass begins (resistance has generally been eliminated by now). Brood ships land, releasing Ripper swarms, which consume organic material and depositing them at the reclamation pools. Capillary towers (and the Brood ships) send the material into orbit. Any remaining surface life is eliminated by Gaunts.
 * Day 80: Ripper swarms board the Brood ships and return to the Hive Fleet. 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 reenters the Warp, in search of fresh prey.
 * Day 100: Imperial navy arrives in response to the distress call, only to find a lifeless planet.

Tyranid Storyline
In Warhammer 40,000, the Tyranids appeared from the eastern part of the Galaxy, on a moon called Tyran, and sent a large fleet of troops (called Hive Fleet Behemoth) directly at the center of the galaxy. They were defeated, barely, by the efforts of the Ultramarines chapter of Space Marines at the Battle of Macragge, although the Ultramarines suffered devastating losses.

Later the Tyranids returned with Hive Fleet Kraken which, instead of throwing one mass of troops against the Imperium, split into countless smaller fleets, each small fleet enveloping whole systems before reinforcements could arrive. The brunt of this new attack was borne by the Space Marine chapters Scythes of the Emperor and Lamenters; the former chapter was almost completely destroyed. At the same time, Hive Fleet Leviathan appeared from "below" the Galaxy (in a 3D sense, on the Z axis) and attacked from two points, cutting off large portions of the galaxy from reinforcements. Just as it seemed the defenses of Segmentum Solar would be tested, the tyranids were distracted by a powerful Ork empire. While this is managing to stall the Tyranids, they are likely to reemerge from these battles and be stronger than ever.

Tyranid Species
Tyranids appear in a multitude of genera, and all have an extremely rapid rate of evolution, adapting to threats in direct response to their presence. Tyranid matter is constantly reabsorbed into biomass reclamation pools to create new species and adapt existing ones to suit the immediate purpose.


 * Hive Tyrants are large and enormously strong Tyranids, acting as leaders of the swarm and a synaptic conduit for the smaller creatures. They are highly psychic and highly mutable, and have a closer connection to the Hive Mind than most other genera. They are monsters at both close combat and ranged attack, with the ability to excel in both. Sometimes they are spawned with wings. Imperial Techno-Magi believe that Hive Tyrants form the repository of the hive fleet's collective consciousness, which means they completely embody the Hive Mind but their destruction does not in any way diminish its presence.


 * Broodlord are another leader organism, regarded as the epitome of the Genestealer breed. The Broodlord is one of the first Genestealer to make planetfall as well. They are devastating in combat and are specifically adept at infiltration on the battlefield to get closer to the enemy. They are very adaptable and highly intellegent.


 * Tyrant Guard are a special species of Tyranid spawned in small broods for the sole purpose of defending the Hive Tyrant. They are large, tough, and difficult to harm, and it is nearly impossible to surpass their defences when they are active in their purpose as bodyguards. Tyrant Guard are completely blind, utterly controlled by the synapse creatures they protect. On occasion Carnifex also benefit from the Tyrant Guard's protection. Tyrant Guard are scientifically rumoured to contain the DNA of defeated Space Marines chapters, but the Imperium considers this blasphemy and denies its possibility.


 * Tyranid Warriors are synaptic foot troops for the swarm. In between the size of a Tyrant and a Gaunt, they serve as psychic resonators and assist in guiding the lesser troops into battle. They are fast and powerful, with the capability to be strong at ranged combat or in close quarters in a similar fashion to the Hive Tyrant.


 * Lictors are large, deadly organisms bred for their stealthy qualities. A Lictor is basically chameleonic in nature, allowing it to blend with its surroundings to hunt and later kill its prey. Lictors are usually only seen when springing a deadly ambush onto an unsuspecting army, unleashing a bio-engineered killing machine within their own ranks. They range ahead of the swarms, performing commando raids of sorts, and gathering information by devouring their victim's brains.


 * Gaunts are the basic staple unit of a Tyranid swarm. They are smaller and less physically powerful than most other Tyranid organisms, but they are extraordinarily adaptable and always attack in large numbers. They are a fully mutable species, and some are grown with extra wings, adrenaline/venom sacs, and even bizarre bio-weapon symbiotes, including the dreaded spike rifle.


 * Gargoyles are essentially winged variants of the Gaunt genus. They follow many similar traits, including a smaller size and physical prowess than most Tyranid organisms. Gargoyles retain most physical traits of Gaunts, however, their lower legs have atrophied to little more than stumps. Like their cousin, the Gaunt, they are capable of being armed with a large host of symbiotic weaponry.


 * Rippers are small, snake-like organisms designed to devour living matter so that new DNA and nutrients can be absorbed by the Hive ships. They are released in the final stage of a Tyranid invasion.


 * Genestealers are ferocius creatures, supposedly derived from human DNA, that are used as a vanguard to the Tyranid invasions. They infiltrate the societies, creating Genestealer Cults, as described under the tactics section above. They are also used as shock troops on the battlefield, where their sharp claws and instinctive close combat skills allow them to tear heavily armed opponents to shreds.


 * Carnifexes – originally known as screamer-killers – are huge, hulking living battering rams, armed with a variety of symbiotic weaponry. Even stronger than the Hive Tyrants, they are used for assaulting fortified positions and tank formations, such as boarding actions.


 * Raveners appear to be related to both Rippers and Tyranid Warriors. These large, snake-like beasts are designed for fast assults against lighter enemies, and dig through the ground to perform surprise raids.


 * Zoanthropes are a type of psychic artillery, whose higly evolved brains swell out of proportion with their bodies. Through their use of psychic powers they can perform a number of roles on the battlefield. Some evidence points to later incarnations of Zoanthropes being improved by Eldar DNA.


 * Biovores are sluggish creatures, whose only task is to grow and launch Spore Mines towards the enemy. The Spore Mines grow inside the Biovore's body, and are then hurled across the battlefield through a muscle spasm. Biovores are supposedly evolved from Orkish gene-stock.


 * Bio-Titans are enormous organisms, evolved as a response to other races' Titans and other super-heavy warmachines. They are (as of yet) the largest land-based Tyranid creatures encountered.


 * Norn-Queens are believed to be the mysterious female counterparts to the Hive Tyrants (in more elvolved fleets this is not the case, for the queens reproduce and splice DNA independently). They lead the Tyranid swarms and direct the evolutionary paths to take. They invariably stay aboard their Hive Ships.


 * Dominatrixes are the Norn-Queen's link to the ground forces. They are huge monsters, almost as large as a Bio-Titan, symbiotically fused with a smaller (Warrior-sized) entity which acts as a psychic link to the Queen abord her ship.