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A Tyranid Bio-Titan leads a Tyranid swarm in an irresistible onslaught against Imperial forces.

A Bio-Titan is a monstrously large Tyranid bioform 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, stand the vast forms of the Bio-Titans. These massive biomechanical war-machines stalk the warzones of the Imperium spitting death and destruction, cutting down their foes with potent bio-weapons.

Their approach is a terrifying sight to behold as they rip apart buildings, tear to pieces infantry and tank formations and even destroy Imperial Titans, Aeldari 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 as their huge bodies are protected by ridged plates of chitinous armour, and even when a lucky shot does penetrate their armoured sides a Bio-Titan is capable of rapid tissue regeneration.

Known Bio-Titan Strains


A Tyranid Hierophant

A Tyranid Viciator, a Bio-Titan strain directly derived from the Hierophant.

The Hierophant Bio-Titan is an immense, hideous creature, towering over the battlefield and bristling with spines, tendrils and symbiote weapons. They are amongst the largest bioforms yet encountered by the forces of the Imperium 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 of the swarm, absorbing huge amounts of damage before smashing into the enemy line with devastating force.

The Hierophant is the Tyranids' largest shock trooper, armed with monstrous Bio-Cannons, multiple claws and razor-sharp blades, armoured with a thick chitinous hide that exudes poisonous spores from rends in its plates. Like all Tyranid bioforms, the Bio-Titan seems to be able to mutate its genome rapidly, evolving new organic weapons and defences.

Other variants of the Hierophant Bio-Titan, such as the less well-known Viciator, have been identified with huge crushing claws or long scythe-like blades, cluster spines and other bio-weapons. How the Tyranids have developed such large biological constructs remains a mystery to the Imperium's Xenos Biologis. Whilst it seems a Hive Tyrant or Carnifex could easily be the result of a further genetic manipulation of the basic Tyranid Warrior genotype, there is no known genetic antecedent among the existing Tyranid bioforms for the Hierophant.

It is speculated by the Magi Biologis of the Adeptus Mechanicus that the Hierophant was derived from the combined genetic strains of the Tyranid Carnifex and the Dominatrix. The forces of the Imperium have learned that 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 Bio-Titans.


A Tyranid Harridan attacks

It is believed that the Harridan Bio-Titan may be derived from a combined strain of the Gargoyle and the Winged Warrior subgroup of the Tyranid Warrior genus. The Harridan is the largest flying Tyranid bioform the Imperium has yet encountered in its bitter war against that inter-galactic alien menace. Harridans are truly massive creatures, likened to the flying drakes and wyverns of ancient Terran legend. They are the largest Tyranid bioform capable of atmospheric flight, soaring through a prey world's skies on vast, leathery wings.

Though they lack the sheer speed of an attack aircraft, it is a brave fool indeed who thinks them an easy target. 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 great fanged jaws around an infantryman.

This creature's fearsome armament makes the Harridan capable of attacking just about any target on the field of battle. The Magos Biologis of the Adeptus Mechanicus 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, while other, far smaller Harridans have also been encountered that were well below the size of what would be considered a Bio-Titan. Instead, these Harridan variants are more like larger and somewhat tougher Gargoyles.


The menacing Tyranid Dactylis

The Dactylis Bio-Titan is speculated to be a larger genetic derivative of the Tyranid Biovore. The Dactylis hurls large Spore Mines at very long ranges. Their forelimbs are long and covered in tightly-corded tendon and muscle that makes a distinctive cracking sound when used to hurl its deadly payload. When initially encountered by the forces of the Imperium, the Dactylis was noted for using the bio-weapon known as a Bile Pod.

This living ammunition is a parasitic creature which feeds off the toxins emitted by the poisonous glands of the Dactylis' cranium. In recent encounters, the Dactylis has shown the Tyranids' innate ability to adapt to any combat situation or tactical need -- its cranial glands have grown a variety of spore-generating colonies that can be used to produce a number of different types of deadly ammunition chosen for their particular utility against specific classes of foe.


A Tyranid Dominatrix

The Dominatrix is a specialised Bio-Titan, psychically commanding the Tyranid forces on the battlefield and providing the highest level of psychic control as an exceptionally powerful -- and valuable -- Tyranid synapse creature. It is a fearsome opponent, for its sheer mass and panoply of bio-weaponry dwarf that of an Imperial super-heavy tank.

The Dominatrix is no unthinking beast –- its level of intelligence is akin to that of the Hive Tyrant, and the strength of its telepathic link to the Hive Mind surpasses even those mighty creatures. Whilst within range of the Dominatrix's psychic aura, lesser Tyranid creatures become little more than an extension of the Dominatrix's will. As a result, a swarm under the Dominatrix's direct supervision functions with uncanny efficiency and a tactical genius that is beyond compare.

Fortunately for the galaxy, such beasts are extremely rare in all but the most advanced Tyranid swarm, for where the Dominatrix treads, doom surely follows. Dominatrixes are the Tyranids' largest known Bio-Titans, and it is rumoured that they sometimes carry the Norn-Queens themselves into battle on their backs.

They are armed with an immensely potent Warp blast weapon, Bio-plasma emitters, and their massive chitinous claws. They also serve as synapse creatures, the Hive Mind's primary battlefield coordinators for the Tyranid swarms. Because of this role, the destruction of a Dominatrix can severely incapacitate a Tyranid swarm that it is responsible for directing, though the firepower required to bring down a Dominatrix is immense.

Bio-Titan Weapons

Close Combat

  • Rending Claws - These are massive versions of rending claws that are only used by gargantuan Tyranid bio-forms like Bio-Titans.
  • Razor Claw - Razor Claws are deadly hand-to-hand combat weapons carried by Tyranid Bio-Titans to enhance their already formidable fighting power. Razor Claws resemble gigantic crab claws, but this basic evolutionary design has been made more lethal by bonding a mono-molecular edge to them so that they can slice through armourplas and ceramite. Razor Claws are also implanted with frag spines like those mounted on Haruspex and Malefactors, and these increase the Bio-Titan's short-range firepower against infantry and light vehicles.
  • Scything Talons - These are massive versions of the chitin scything talons found on smaller Tyranid bio-forms.
  • Stinger Salvo - Stinger Salvos are used against infantry and lightly armoured vehicles at close range. The Stingers themselves are fans of long, needle-like protuberances which contain a vein of lethal corrosive venom. The stings are segmented and when the Bio-Titan directs a pulse of venom into them the tips are launched with tremendous velocity. This reveals the sharp tip of the next segment of the needle and makes it ready for firing. Salvos of the high velocity Stingers are short-ranged but devastating, riddling targets with slivers of bone and corrosive poisons.


  • Bile Launcher - Bile Launchers work by belching a jellied lump of cankerous slime which is corrosive enough to burn through flesh and bone in seconds. Armoured targets may last a little longer than others but even they will collapse into piles of pitted and rusted metal within a few Terran minutes. Worse still, the Bile Launcher can have a considerable splatter radius if it strikes its target. These smaller droplets of acidic slime are unlikely to damage battle tanks but they can still kill foot soldiers who fail to take cover.
  • Bio-Cannon - Bio-Titans commonly carry large, triple-orificed symbiote weapons which appear to function in a similar manner to the Bio-Cannon mounted on an Exocrine. The heavy cords of muscle that ridge the barrels of the cannon accelerate its ammunition of chitin shells to a speed at which they punch through armour as if it were cardboard. A hardened penetrator core at the centre of the shell penetrates the target in a small explosion of shrapnel and carries the spores of a pernicious slime fungus into it. Large targets that sustain a hit from a Bio-Titan's Bio-Cannon are often rotted from the inside out within minutes of impact.
  • Cluster Spines - Cluster Spines are similar to the Frag Spine implanted onto Haruspex and Malefactors for close range, anti-personnel work. They are fired by a muscular contraction and use explosive cellular expansion to detonate on impact and spray razor-sharp chitin plates over the target area. The cluster spines implanted onto Bio-Titans are larger, more densely packed and fire in groups to achieve maximum saturation of the target.
  • Pyro-Acid Spray - Pyro-Acid Spray is undoubtedly one of the most fearsome weapons in the Bio-Titan's arsenal. The spray fires a triple jet of highly corrosive acids which melt through plascrete and steel like wax. The interaction of the acids also produces a great release of heat, such that the jets ignite as they leave the nozzles of the spray and the target area is quickly covered in licking flames and explosions where the burning acid has swept over it.
  • Spore Pods - Many Bio-Titans carry swollen pods of virulent spores implanted into their chitinous limbs. When they explode, the air around the Bio-Titan is filled with deadly spores which will pierce the surface of anything warm they touch and send burning, threadlike growths shooting into it. Bio-Titans use nerve impulses to detonate the pods, either as an intense cloud in a small area or as a broad bank of spores to sweep a larger area. Though each Spore Pod is emptied when it is used, a single Bio-Titan carries enough Spore Pods to last for an entire battle.


  • Advanced Space Crusade Booklet (Board Game)
  • Chapter Approved: The Second Book of the Astronomican (2001), "Tyranid Monstrosities - A Guide to Spawning," by Pete Haines, pg. 103
  • Codex: Tyranids (6th Edition), pp. 37, 40, 51, 72, 151, 154,
  • Codex: Tyranids (5th Edition), pg. 21
  • Codex: Tyranids (4th Edition), pp. 4-5, 17-18, 27
  • Epic: Hive War (2nd Edition) by Andy Chambers, pp. 64-66
  • Imperial Armour Volume Four - The Anphelion Project
  • Warhammer 40,000 Collectible Card Game (Viciator Card)
  • White Dwarf 146 (UK), "Space Fleet: Tyranid Hive Fleets - The Hivefleet," by Andy Chambers & Andy Jones pg. 21
  • Warriors of Ultramar (Novel) by Graham MacNeill