Rak'Gol - Anatomy and Physiology: The typical Rak'Gol possesses eight limbs. Normally, when not in pursuit of prey, they tend to walk upright on four limbs; using the other four to perform various other functions. However, when in pursuit of prey, they can easily shift into using up to all eight limbs for locomotion. A Rak'Gol's upper four limbs possessadaptable grasping appendages; they can change the musculature to use these as hands, complete with opposable digits, instead of grasping feet. These appendages are strong enough that an adult Rak'Gol can actually climb and run completely upside down, attached to virtually any surface. The Rak'Gol also possess prehensile tails that assist in balance. In addition, the Rak'Gol have keen senses of smell and sight, and these are often enhanced through their use of cybernetics and bionics. When standing upright, the Rak'Gol tower over humans, standing at least 2.6 metres tall and weighing up to 175 kilograms. To humans, this xenos species appears reptilian, however, their skin does not possess the tell-tale scales that many reptiloid species exhibit. Rather, their skin is a rough-hewn texture, almost stonelike -- very similar to ancient Terran lizards. Non-modified Rak'Gol possess two eyes deeply recessed in their skulls, and a tympanic-like membrane for hearing.The dual taints of the Warp and radiation are commonly found among the Rak'Gol. The radiation may be a consequence of the "fission-pulse" nuclear thermal drives found in their vessels. However, it may be that the species seeks this out as a means of inducing additional mutations among their ranks. The seneschal and information broker Nathin Thsanthos has observed that he is unsure which option is more terrifying, that the Rak'Gol deliberately seeks out corrupting mutation, or that the species is so consumed by bloodlust and rage that they no longer have the interest or ability to conduct basic maintenance on their vessels. While some mutations are clearly due to the depredations of the Warp, others seem more consistent with those developed following extended exposure to ionising radiation. Thecombination of these two influences clearly affects the species' gene pool, which has resulted in substantial variation between specimens found in different regions of the Expanse. At the same time, Imperial reports have not identified any tribal or cultural iconography that associate with any of these genetic variants. This suggests, but does not confirm, that the Rak'Gol may lack the necessary cultural sophistication to develop tribal cultures.Members of the Magos Biologis have marvelled at remains recovered from Rak'Gol conflicts. Studies indicate that the species is egg-laying and that Rak'Gol undergo extensive physiological changes over the course of their maturation. Further, their reproductive methods appear to involve a trinary breeding scheme that is dependent upon the age and stature of the individuals involved. Some reports suggest that biochemical and physiological changes may occur in the Rak'Gol based upon their social standing within their communities. As the xenos attain specific levels of authority, this may trigger shifts in their reproductive mode. However, these factors cannot be confirmed until live specimens are studied over an extended period. Astropaths have been unable to consistently divine future attacks, even with the assistance of the Emperor's Tarot, as the simple brutality occurs at unpredictable intervals across a huge range of locations. The xenos infest the Unbeholden Reaches more so than others, but attacks have occurred inconsistentlyin many other locations. Among voidsmen, many legends have circulated that the Warp itself often places the xenos vessel in ideal locations to launch an attack at the most inconvenient time possible. These legends are most common within theregions of space where the Rak'Gol are most active -- a factor that is hardly coincidental.In sharp contrast, based upon their exploration patterns through the Koronus Expanse, there may be more of a pattern to at least some of the Rak'Gol attacks than first appears. A number of these assaults occurred on worlds where xenoarchaeologists have identified the remains of civilisations lost long before the first Rogue Traders passed through the Maw. This suggests that the seemingly mindless Rak'Gol have the motivation and abilities necessary to carry out a searchfor something lost. Thus far, however, no researcher has been able to discover what could be valuable enough to send them out across the Expanse. This presents a challenge to Imperial forces attempting to constrain the Rak'Gol. Without a known target, it is far more difficult to provide consistent protection against thealien incursions. Their volatile and unpredictable natures only exacerbate the problem. Ultimately, there are far too many worlds containing the remains of shattered cultures within the Koronus Expanse to hope to protect them all. The mostprominent Rogue Trader houses in the Expanse -- Winterscale, Chorda, and Saul -- have promised great rewards to the persons who discover the source of these foul aliens, so that they might descend upon their world and cleanse it with the wrath of their considerable fleets. However, thus far no one has managed to accomplish this.