Bio-Titan

A Bio-Titan is a monstrously large Tyranid biomorph intended to counter the greatest war engines deployed by the other intelligent species of the Milky Way Galaxy. Towering above the battlefields, leading the swarms of lesser Tyranid creatures, tower the vast forms of the Bio-Titans. These massive organic, biomechanical war-machines stalk the warzones spitting death and destruction, cutting down their foes with massive bio-weapons. Their approach is a terrifying sight to behold as they rip apart buildings, tear apart infantry and tank formations and even Imperial Titans, Eldar Wraithlords or Ork Gargants with their armoured claws and ripper tentacles. Propelled relentlessly forward on their powerful legs, these horrifying creatures smash enemy defences into rubble with their deadly arsenal of bio-weapons. In return their enemies can do little - even under the heaviest fire, Bio-Titans are notoriously hard to kill. The Tyranid's enemies try even harder, targeting their largest weapons, but the Bio-Titan's huge bodies are protected by ridged plates of chitinous armour, and even when a lucky shot does penetrate their armoured sides the Bio-Titans can regenerate!

Carnifex/Dominatrix Strain
It is speculated that the Hierophant was derived from the combined genetic strains of the Tyranid Carnifex and the Dominatrix, respectively.
 * Hierophant - The Hierophant Bio-Titan is an immense, hideous creature, towering over the battlefields and bristling with spines, tendrils and symbiote weapons. They are amongst the largest bio-creatures yet encountered amongst the swarms of the hive fleets, comparable in size and power to an Imperial Titan. A brood of Hierophants are likely to be at the forefront of a major Tyranid attack - striding forwards, drawing enemy heavy weapons fire away from the lesser creatures, absorbing huge amounts of damage before smashing into the enemy line with devastating force. The Hierophants is the Tyranids' largest shock troop, armed with massive bio-cannons, multiple claws and chitin blades, and armoured with a thick chitinous hide that exudes poisonous spores from rends in the plates. Like all Tyranid creatures, the Bio-Titan seems to be able to mutate rapidly, evolving new weapons and defences. Other variants of the Hierophant biotitan have been identified with huge crushing claws or long scythe-like blades, cluster spines and other bio-weapons. The development of such large bio constucts remains mystery to the Imperium's Biologis. Whilst it seems a Hive Tyrant or Carnifex could easily be a further evolution of a Tyranid Warrior, there is no other connection from any other creatures to the Hierophant. Combating Hierophants is simply a matter of applying the heaviest firepower available; large ordnance weapons and heavy artillery have so far proved the only effective weapons in destroying biotitans.
 * Dactylis - The Dactylis Bio-Titan is speculated to be a larger derivative of Tyranid Biovore. The Dactylis hurls large Bio Spore Mines to long ranges. Their forelimbs are long and covered in tightly muscled flesh. They use Bile Pods, a larger version of Poison Spore Mines, and are similar in appearance to the Exocrine.

Ravener Strain
It is speculated that the Exocrine Mawloc and Trygon are from the Ravener subgroup of the Warrior Genus of Tyranids.
 * Exocrine - The Exocrine is undoubtedly the most specialized of all the Tyranid bio-war machines, bred for the purpose of striking at the foe from long range while more conventional Tyranid constructs close in to attack with tooth and claw. The highly developed forelimbs of other Tyranid creatures appear to be absent from the Exocrine body form, but the distinctive bony head frill and long tubular bio-cannon were originally the creature's forelimbs. These have fused together and expanded considerably to achieve their new purpose. The Exocrine fires high velocity chitin shells, which with the aid of their silicon-based penetrator core, can punch through even Titan armor with ease. The shells are simple but deadly, penetrating the target and releasing an acidic slime fungus which replicates rapidly and cause severe damage to complex systems. More short range destruction is supplied by outgrowths of virulent spores on the creature's carapace. An autonomic nerve function fires in the presence of non-Tyranid bioforms with the speed and hitting power of bolters. Exocrine are driven by instinct and are liable to become confused and uncoordinated unless they are controlled by the Hive Mind. The Exocrine's natural instincts have been genetically altered to make it Nest, remaining stationary and hurling its chitin shells at the nearest enemy in the firing phase.


 * Mawloc - Mawlocs are huge worm-like creatures with massive razor-toothed maws that act as the entryway to their equally cavernous gullets. These loathsome creatures are outriders to the Tyranid swarm, burrowing deep beneath the ground to bypass the enemy's front line defences. Once past the outer perimeter, a Mawloc burst forth in a shower of dirt and shattered stone to run rampant through supply lines, command posts or artillery batteries, only to vanish back below ground as forward units are recalled to the fight. Severe tremors are the only warning of a Mawloc attack, making defence duty a particularly harrowing experience. Most of a Mawloc's victims are swallowed whole, there to be painfully digested. Anything too large to swallow is pounded flat by the Mawloc's muscular tail before being devoured.


 * Trygon - Trygons resemble a very large version of a Ravener. This vast serpentine creature is so colossal, that it even towers over the mighty Carnifex. It is heavily armoured, covered from head to tail with a carapace of shifting plates. A Trygon's claws are fearsome weapons in close combat, but they also allow it to burrow through practically any material. The Hive Mind uses the Trygon to excavate a massive network of underground tunnels so that other Tyranid creatures may use these tunnels left in the Trygon's wake, scuttling unseen as battle rages overhead. The emergence of a tunneling Trygon therefore often heralds a larger Tyranid attack, with hordes of creatures pouring out of the tunnel shortly after its emergence.

Winged Strain
It is speculated that the Harridan is from a combined strain of the Gargoyle and the Winged Warrior subgroup of the Warrior Genus of Tyranids.
 * Harridan - The Harridan is the largest flying Tyranid creatures the Imperium has yet encountered in it bitter war against the inter-galactic alien menace. Harridans resemble a very large Gargoyle with great wings. They are the Gargoyles' 'brood-mothers' and carry their 'young' into battle. Circling high above, the Harridan waits patiently before diving down over the battlefield, strafing its foes with bio-cannons or swooping low to rake a tank with its two massive claws, or snapping its massive fanged jaws around an infantryman. This creature's fearsome armament enables the Harridan capable of attacking just about any target on the fields of battle. Magos Biologis have noted that Harridans have been encountered in a variety of sizes. Some are huge, upwards of 30 metres in length with a sizable wingspan of 40 metres, other far smaller Harridans have also been identified.

Other Bio-Titan Strains

 * Dominatrix - The Dominatrix is a specialised Bio-Titan, commanding the forces on the battlefield and providing the highest level of psychic control. They are the Tyranids' biggest known bio-titans, and it is rumoured that they sometimes carry the Norn Queens themselves into battle on their backs. They are armed with a warp blast weapon, bio-plasma, and their massive claws. They are also a synapse creature.


 * Norn-Queen - Tyranid Norn-Queens fill the role of the "queen" of the hive, similar to that of a queen ant, termite, wasp or bee. As far as it is known, they are bound to a Tyranid Hive Ship and cannot leave it. They are responsible for the engineering and birthing of new Tyranids of every known bioform and psychically communicate with the other Tyranid synapse creatures, transmitting the will of the Hive Mind. A Norn-Queen is always in the most protected Tyranid aboard a Hive Ship, so the humans of the Imperium have been unable to garner much data about them. The death of a Norn-Queen will destroy the synaptic abilities of the Tyranids to communicate, rendering them barely-sentient beasts: the death of the Norn-Queen at Tarsis Ultra caused the entire Tyranid swarm to turn on each other and become feral beasts. Norn-Queens also, to some degree, control the evolutionary course of the Tyranid swarm. Upon arrival at a new world they intend to strip of its biomass, the Tyranids disgorge the "Alpha" wave of creatures, which contain the genetic material of the Norn-Queen itself. These creatures then relay telepathic information to the Queen on the new world's environmental conditions and battlefield requirements, which spawn the second and subsequent generations of Tyranid bioforms, sometimes with tens of thousands of casualties in the collection of the data. Capture of an Alpha wave Tyranid can lead to the creation of a neurotoxin which can directly affect the Queen, as was done by the Ultramarines during the invasion of Ultramar by Hive Fleet Behemoth. When a Norn-Queen is killed, the psychic signal of its death causes hive ships to calve, creating more Norn-Queens. This is known as the Hydra Effect.


 * Tervigon - The Tervigon is a massive creature, with a towering spined carapace that shields a swollen abdomen. Despite its massive size, the Tervigon can be deadly in close-combat, shifting its weight onto its rear legs and scything its claws back and forth in crushing arcs. The Tervigon should also not be underestimated at range - its carapace concealing banks of cluster spines that can be fired at a considerable distance. Yet despite its fearsome weaponry, the Tervigon's true threat lies within. Each Tervigon is a living incubator beneath whose lumpen carapace dozens upon dozens of Termagants slumber in a state of near-life. The Tervigon spawning its dormant broods at will, so that a foe engaging it will soon find itself assailed by waves of skittering Termagants. The only way to end this menace is to concentrate all firepower on the Tervigon and slay it. The resulting symbiotic backlash inevitably killing its spawn. Whilst traveling through space, Tervigons do not slumber in a dormant state. Instead, they roam the ship's cavernous innards. Should they detect intruders, it can spawn an army of frenzied Termagants to repulse the foe whilst using its potent synaptic link to awaken additional warriors.