Censor’s note: some content present in the original version of this article has been expunged in compliance with Alliance information control policy.
Burster-stalker is the common name for Omniparasitoid 1-YRVN-6, an aggressive and highly dangerous organism first discovered on the fifth-largest moon of the gas giant Yarvin. Burster-stalkers (or simply bursters) are sapient, and they are suspected to possess the capacity to construct a pre-sigmoid civilization. Owing to the extreme difficulty of safely studying this race, it is not known whether any burster-stalker civilizations currently exist, though certain relics suggest multiple such civilizations may have existed in the distant past. Burster-stalkers are invariably hostile to other sapient races; in every known case where they have displayed kindness, forbearance, and diplomatic behavior, this has eventually proven to be a ruse to coax their prey into dropping its guard.
The burster-stalker life cycle has four stages: 1) egg, 2) larva, 3) endoparasite, and 4) drone or queen. The ellipsoid eggs measure about half a meter from bottom to top. When an egg detects—via air and ground vibrations, temperature changes, molecules that land on its shell, and, possibly, other factors—that one or more large organisms not belonging to its clade1 are present, it hatches. The larva that emerges has a disc-shaped body usually around twenty centimeters in diameter, five pairs of three-jointed legs, and a prehensile tail more than twice its body length tipped with a venomous stinger. It is armored with a mottled exoskeleton (dark green, gray, and black are almost always the dominant colors) that is resistant to most small-arms fire. It can move with great speed, almost as easily on slippery walls and ceilings as on rough-textured ground. It controls the amount of venom injected by a sting—a light dose causes unconsciousness, nausea suppression, and short-term memory loss, while a heavy dose is lethal.2
When a larva has rendered a suitable prey organism unconscious and amnesiac, it attaches itself to the area around one of the prey organism’s deep orifices and inserts its prehensile ovipositor, which can extend to a length nearly equal to its tail’s. For oviposition in a hominoid3 victim, a larva typically selects the mouth, though some have been observed to select the anus or vagina. When the mouth is selected, the larva almost always extends its ovipositor down the trachea and implants its embryo in one of the lungs. In addition to implanting the embryo, it secretes a small amount of nourishing fluid containing a number of psychoactive compounds and mutagens. This fluid is highly viscous, and its outer layer swiftly solidifies, forming a cyst around the embryo. A burster-stalker larva invariably contains only one embryo. Once the implantation process, which can take anywhere from two to twenty minutes, is done, the larva detaches from the prey organism and finds a place to hide. Burster-stalker larvae cannot feed; they hatch with all the nourishment they will ever have. For this reason, their lifespan is quite short, especially since they donate almost all of their remaining nourishment to the embryo during oviposition. It is rare for a larva to live for more than an hour after finishing oviposition, or for more than fifty hours after hatching whether or not it finds a home for its embryo.
The normal time range of the endoparasite’s gestation is between four hours and six days. If the endoparasite is programmed to develop into a queen, gestation normally takes between two and fifteen days. Though gestation can be slowed by procedures such as coma inducement and cryogenic preservation, in no case has it been halted entirely. The longest known gestation period is one hundred and twenty-nine days. In this experiment, the host was cryogenically preserved and cooled as much as possible without pushing the body beyond hope of resuscitation. The endoparasite managed to generate enough heat to continue its development at a gradual pace. Development of a queen endoparasite is more difficult to retard than development of a drone; the longest known gestation period for a queen is forty-eight days.
Mutagens and psychoactive compounds initially implanted by the larva and later secreted by the endoparasite can cause a variety of physical and behavioral changes in the host. These include:
Selective numbness and selective proprioception impairment that prevent the host from noticing the growth of the endoparasite in their body
Elevated or extreme hunger, which can develop into pica for substances conducive to the endoparasite’s development
Increased volume and frequency of waste excretion
Impaired intelligence
Persistent fatigue
Uncharacteristic introversion and secretiveness
Strong aversion to the insertion of objects into the flesh, e.g. hypodermic needles
Gradual rearrangement of tissues and organs immediately surrounding the endoparasite, to provide room for its increase in size; this is facilitated by motile tendrils that extend from the endoparasite’s body
The endoparasite may also grow temporary external organs to “fill in” for any important host organs that are damaged by its gestation. In hominoids, the endoparasite usually migrates out of the initial lung cyst, sealing its exit except for the formation of a sort of umbilical cord that connects the endoparasite to the cyst to ensure easy access to any remaining larval secretions. The endoparasite remains centered within the ribcage as it increases in size; it can reach a length of up to one-sixth its host’s height before emergence. Often, when the eruption of the endoparasite is imminent, the host will feel compelled to seek out a secluded location away from other members of its clade. Due to the memory loss inflicted by the larva’s sting, and the mental changes caused by substances secreted by the larva and the endoparasite, the host is in most cases unaware of their condition until the endoparasite begins to force its way out of their body.
The burster-stalker endoparasite customarily emerges by violently tearing and ramming its way through the host’s flesh.4 If centered in a hominoid’s ribcage, it will brace itself against the spinal column with its legs, lower body, and tail, and—through a combination of biting, wriggling, thrusting of its head, and use of its arms—forcibly widen a gap between two ribs, partially break the ribcage (usually separating multiple bones from the sternum), and breach the chest. The newborn burster will then squirm out through the hole it has made. If potentially hostile organisms are present around it, it will attempt to flee to a safe location, though even at birth it is capable of inflicting grave injury on beings much larger than itself. A newborn burster has fully functional arms and legs, as well as a tail already equipped with a tiny venomous stinger. It does not use this stinger on its host; the sharp tip remains “sheathed” until the burster has fully emerged from the body in which it gestated.
In an environment with sufficient food, a newborn burster can develop into a fully grown drone in as few as three days. Mature drones range from six and a half to eight feet long from the face to the base of the tail; the prehensile stinger-tipped tail might extend for another five feet. Their armored bodies are highly resistant to conventional mêlée and infantry weapons. Burster-stalkers have been observed to withstand such methods of attack as machine gun fire, impasers (impaling lasers), plasmathrowers, acid jets, and ultrashortwave radiation beams, fighting back with enough success to kill their attackers. Any of these methods might kill or seriously wound a drone; however, none can do so reliably. Drones have been known to recover from tank shells, small missile impacts, freefalls of hundreds of feet, prolonged submersion in caustic fluids, prolonged exposure to extreme heat or cold, and prolonged isolation in ultra-high vacuum. They possess the strength to tear through sheet metal, break bulletproof glass, and crush the bones of most organisms of a size comparable to their own. They can also use oral glands to projectile-spit exotic superacids; the chemical identity of the acid used varies according to what substances the drone has consumed.
Burster-stalker drones have a hominoid body plan and can move either bipedally or quadrupedally, though they prefer four legs for fast movement. They are capable of sprinting at over seventy miles per hour. Their faces lack noses and conventional eyes, but the armor plate that ends at the upper lip features shallow divots through which various radiation-sensing organs collect data. Matching rows of small armor “caps” running from the lower cheeks to the neck can be retracted beneath the skin to unveil sensitive ears that can be used in tandem with the mouth to perform echolocation. The mouth contains sharp fangs with which the drone tears off chunks of food to swallow whole. Burster-stalkers are highly omnivorous—in addition to animals, plants, fungi, and processed foodstuffs, drones have been known to eat such materials as fabric, soil, peat, plastic, gasoline, crude petroleum, styrofoam, fecal matter, wax, volcanic ash, corrosive cleaning agents, spacecraft engine coolants, and, in one case, all the non-gaseous contents of a collection comprising a small sample of every non-transuranic chemical element. Drones routinely engage in cannibalism, both of each other and of dead larvae and empty eggs, though they usually do not attack each other without some specific motivation (e.g. a dominance struggle between rival hives).
A long phalloid crest extends for two to three feet from the back of a burster-stalker drone’s head. This crest contains a complex system of inflexible tubes and inflatable chambers connected to the drone’s respiratory system and can therefore be used as a kind of wind instrument. The sounds produced are somewhat muted when the drone’s mouth is closed, less so when the mouth is open. Drones can “speak” or “sing” in both single tones and multiphonics; many of their multiphonics create sum and difference tones heard much more easily by other drones than by prey organisms. The timbre of the burster-stalker’s “crest voice” varies but is usually described as a shrill, eerie sound with a quality somewhere between that of a flute and that of a clarinet. Drones use their crest voices to communicate in sapient language. They often use a degenerate form of “Tekeli’ese,” the language of the pentapods; it is not known whether this is their original tongue. Culturally isolated hives—that is, hives entirely descended from eggs that had lain dormant for thousands of years, without contact from other members of the clade—have been seen to develop their own languages seemingly from scratch. Linguistic analyses reveal vast gulfs between the “scratch languages” of different culturally isolated hives, suggesting that the structures of these languages are mostly not determined by the eggs’ genetic code. Drones often use their crest voices to mimic the vocal cadences or music of prey organisms. There exist unverified accounts of highly talented musicians from prey clades being specifically selected to incubate queen endoparasites.
Queen bursters can reach sexual maturity as few as ten days after emergence from the host, though most take at least twice as long. Within a hundred days, a typical burster-stalker queen will have reached a length of thirty to forty feet, excluding the tail. The body plan of a young queen is similar to that of a drone, with the exception of a swollen abdominal area devoted to egg production. Queens are the only burster-stalkers that can produce eggs. Drones have prehensile phalloid “tongues” whose tips can secrete sex cells; a queen will regularly extract samples from these organs from the drones in her hive. In the absence of suitable drones, a queen can reproduce parthenogenetically, extracting sex cells from her own phalloid tongue. Queens are believed to exert conscious control over which, if any, of their eggs contain larvae whose embryos can themselves gestate into queens. A queen rarely leaves the central regions of her hive; if she ventures far, it is usually to confront an existential threat to the hive, or to engage in single combat with a queen from a rival hive. A queen born in a hive that already has a queen will attempt to establish a satellite hive nearby; when iterated, this process can generate vast networks of allied hives. A queen’s growth slows dramatically after she reaches forty to fifty feet, but it never completely stops; therefore, old queens are immobilized at the center of the hive by their own bulk, and their bodies eventually grow into their surroundings like tree roots.
Most burster-stalker eggs do not contain larvae whose embryos can become queens; those that do are visually indistinguishable from the rest. A queen-capable egg can “decide” whether to become a queen egg based on information it senses in its environment; likewise, a larva that hatches from a queen egg can decide whether to make its embryo queen-capable. The embryo itself, once implanted in the host, can also make such a decision early in its gestation. If all three immature stages of the organism—egg, larva, and endoparasite—decide not to shut down the genes that enable queen development, a new queen will be born.
A cache of eggs that does not include any queen-capable eggs need not result in a sterile hive. If a drone determines that there are no queens or queen-capable eggs in its vicinity, it can use its phalloid tongue to inject sex cells into an egg, prompting the development of a “synthetic queen.” The more drones contribute genetic material to this egg, the healthier the resulting queen will be. Even in the absence of eggs, the creation of a synthetic queen is possible—a group of drones can hijack the reproductive system of a female prey organism to conceive an embryo capable of gestating into a hybrid entity that can lay burster-stalker eggs. In this method, each drone [CONTENT EXPUNGED]; the resulting mix of cells coalesces into the embryo, which develops much as a normal burster-stalker endoparasite would. As with the egg-injecting method, the more drones involved, the healthier the resulting queen. Hybrid synthetic queens occasionally have the ability to reproduce with members of their host’s clade; this is thought to explain the presence in Alliance space of a handful of clades whose predatory behavior and physical appearance bear an eerie resemblance to those of burster-stalkers.
A fully developed burster-stalker hive usually contains dozens or hundreds of prey organisms imprisoned for use as endoparasite hosts. Drones strive to learn their captives’ food preferences in order to keep them as healthy as possible. Rarely, a host survives the emergence process. In such cases, the drones of the hive treat the host with far less violence and hostility than is typical; they may nurse the “surrogate” back to health or even allow them to leave the hive. Drones usually do not treat surrogates from rival hives with decreased hostility. Surrogates rescued by Alliance military forces often display reduced fear of burster-stalkers from their hive and reduced eagerness to fight them; they might be particularly reluctant to inflict harm on the drone they gestated. If a surrogate shows the potential to survive repeated gestations, the hive may keep it imprisoned for that purpose. The peculiar selectiveness of the damage a newborn burster causes its host—the burster will, if it can, avoid harming the heart, major arteries, lungs, and digestive tract—has led some scholars to suggest that burster-stalkers were originally symbionts of a hominoid clade with a powerful healing factor, such that hosts could reasonably be expected to make a full recovery from the trauma of emergence. It has even been theorized that burster-stalkers once [CONTENT EXPUNGED].
In the absence of special military privileges, Alliance law mandates that any citizen who encounters one or more non-egg-stage burster-stalkers must make a good-faith effort to kill them. The default punishment for failure to follow this directive is indefinite imprisonment in the Sea of Ecstasy.
As species is not a well-formed category, the term clade, with disambiguation provided by context, is preferred.
What is “light” and what is “heavy” can vary greatly from one prey clade to another; larvae that initially misjudge their doses have been observed to learn quickly.
Here, “hominoid” means approximately “possessing a bipedal, bilaterally symmetric body plan with a frontal-faced head and an oral cavity on the lower part of the face,” not “belonging to the superfamily Hominoidea.” This body plan is common throughout the Local Cluster, due both to convergent evolution and to [CONTENT EXPUNGED].
In the process, the endoparasite sheds any tendrils or other external organs grown for the purpose of stabilizing the host’s body during gestation.