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A Cyber-Mastiff utilised by the Adeptus Arbites

The Cyber-Mastiff is a robotic or cybernetic construct for use in combat and hunting that is based on the form of large hunting dogs. It generally stands hip-high or so to an adult human and over a metre long from tip of head to hindquarters, its lean body composed of high-speed actuators and motor systems over a carbon skeleton and wrapped in angular, interlocking armour plates. On some worlds the dogs are actually cyborgs who retain some organic internals, generally muscles and nerves, and on some Frontier Worlds "Cyber-Mastiffs" are in fact conventionally-bred hounds with armour and controller grafts. Adeptus Arbites models are almost completely mechanical, with only the central nervous system using vat-grown or printed organic layers to take the cortical imprint. Heavily-sprung legs give the units tremendous sprinting speed on their splayed and sharpened steel claws. Their jaws use fibre actuators to snap with blinding speed, with backup hydraulics to exert merciless, crushing force. There are often multiple adjustable teeth in their mouths for different attack patterns: a set of blades to clip off their quarry's gun-hand, or a set of armour-piercing spikes that can grip flesh. The design takes advantage of the dog's cortex's ability to process tremendously intricate sensory input, particularly scent, and most Subrique Pattern mastiffs have a battery of sense and tracker systems loaded into their headpieces, made possible by the unique chemical reagents mined from the ocean's toxic sludge. "Vanes out" is the order for the mastiff handlers to extrude their dogs' specialised sniffer arrays and has become a common idiom among the Arbitrators serving in Hive Subrique on the world of Landunder for maximum alertness.

Cyber-Mastiff Handler

A female Adeptus Arbites with a Cyber-Mastiff and Psyber-Eagle in pursuit of her quarry

Handlers spend many standard years with their hounds, training them for the hunt and the kill. They spend countless hours running their charges through drills and training simulations, implanting commands and attack patterns into their cogitator-augmented brains through sheer repetition and rote. All of this training is culminated on the beasts' first actual hunt, in which the handler takes his charges into the field to be put to the test. Giving signals directly to their built-in Vox receivers, the Cyber-Mastiff Handler is able to coordinate extremely complex engagements through a dizzying number of pre-programmed patterns. Using powerful Auspex arrays and visual sensorium data from the beasts themselves, Handlers can control their beasts at incredible ranges, directing their attacks from several Terran miles distant.

Cyber-Construct Use

It is not unheard of for individuals who are not Cyber-Mastiff handlers, or who are not equipped with a Constructer Interface to make use of Cyber-Constructs. While a trained Adeptus Mechanicus agent, with the proper augmetics is vastly more capable of repairing, controlling, and training these creatures, they are not alone in their use. Anyone equipped with a Constructer Array can program his Cyber-Construct to obey the vocal (or Vox) commands of another agent. This is limited, and cogitation patterns that would normally process evasion and attack movements must instead decipher human speech and intent. To avoid confusion, many users give the beast a designation, commands that may be easily addressed, so that it does not interpret random words in other speech as an order.

Notable Cyber-Mastiff Variants

  • Subrique "Bullpup" Cyber-Mastiff- This heavy duty Cyber-Mastiff is most often employed by the Calixian Arbites, custom designed at the commission of Lord Marshal Goreman's predecessors by the Adeptus Mechanicus within Hive Subrique. The beast is carefully crafted as a true terror weapon, a massively built and heavily-armoured steel construct of considerable bulk. Equipped with sub-sonic Voxhailers that continually emit a selection of low frequency vocalisations designed to trigger fear in the local population where they are deployed, this mode finds frequent use during intense riots. Capable of shrugging off most small arms fire and of bringing down even large groups of well-armed opponents, the Bullpups tend to be used as a final weapon to launch at the Arbites' foes, preventing a civil uprising from turning into a civil war. Bullpups are equipped with shock jaws which can also double as Chainblade weapons. The construct also has magnetic locking feet and jaws which enable the creature to lock on to a target and hold it in place.
  • Subrique "Bloodhound" Cyber-Mastiff - This variant of the Cyber-Mastiff crafted in the bowels of Hive Subrique makes use of the rare chemicals contained in Landunder's oceans. Used to translate airborne particles in quantifiable data, the chemical "sniffers" make the Bloodhound optimised for scent-based tracking roles. While many Cyber-Mastiffs have some tracking ability, the programming and routines implanted within the Bloodhounds are trained by some of the finest handlers available in the Calixis Sector. Once implanted in a light Cyber-Mastiff chassis, the animal instinct and repetitive training is linked to some of the most sophisticated olfactory sensors available in the sector (and some claim the Imperium). This formidable equipment suite is combined with an insidiously effective training regimen, which electrically stimulates the cogitator's cortical centres upon completion of a successful "find". This practice causes the Bloodhound to become obsessive and tireless in its duties; the creatures have been rumoured to track targets for hundreds of Terran miles without sleep or rest, although this may be a tall tale used to intimidate criminals into submission.
  • Malfi Pattern Eliminator-Mastiff - Though Malfian Enforcers are known for being generally as corrupt and amoral as the rest of the planet, certain precincts have a particularly dark reputation. These enforcers are known to eliminate anyone in the name of "justice," so long as they receive sufficient quantities of Thrones in return. Through their actions, the Eliminator-Mastiff has come to represent their twisted perversion of justice. A heavily modified Cyber-Mastiff, the Eliminator-Mastiff has no protocols or programming for bringing down its targets alive. It simply tracks, hunts, and kills any target loaded into its sophisticated spoor-identifying protocols. Most are equipped with a pair of overcharged las-weapons in pods mounted on the shoulders, leaving the head free to mount a mouthful of reciprocating Chainblades. However, some models have been modified to carry even more powerful weaponry.


  • Dark Heresy: Book of Judgement (RPG), pp. 26, 44, 72-74
  • Dark Heresy: The Inquisitor's Handbook (RPG), pg. 143
  • Fanatic Magazine 1, pg. 5
  • Fanatic Magazine 5, pg. 7
  • Inquisitor: Rulebook (RPG), pg. 91