Rarig
Rarigs (pronounced /ˈrɑrɪg/ or /ˈrærɪg/) are a type of aneka that can change its features between those of its primary and secondary forms, but must maintain parts of each form, whatever overall form it takes. While they are sometimes confused with turnskins—and certainly have some similarities to them—there are important differences, this inability to fully take on one form or the other being foremost among them.
When it transforms, a rarig may choose which of its parts to assign to which of its forms, so long as it does not allot them all to one or the other. A rarig with a human primary form and a cervine secondary form (a chodeer) may choose to appear almost fully human, but with antlers, for instance, or a stag's muzzle—or both. More often, however, rarigs find it useful to hide their discrepant features if possible; the rarig of this example may therefore choose, for example, to become fully human save that one leg ends in the foot of a deer, concealed in a cleverly designed boot. Conversely, if it mostly takes the form of a deer, the rarig must maintain one feature of a human—perhaps having human ears on its cervine head, or perhaps giving itself not a deer's elegant belly but a hairless human gut. As long as it doesn't fully take on either its primary or secondary form, a rarig can take on any sort of intermediate form it wishes to, but most spend most of their time as almost one form or the other. Rarigs tend to settle into a few different configurations they're comfortable with, and take on those forms almost exclusively; some go so far as to altogether forget how to take on any forms but those, though they may regain the knack with effort.
Strictly speaking, it's not completely correct that a rarig cannot fully take on one of its forms; rather, a rarig that does fully take on one of its forms experiences dire consequences. This event is known as rarain. The most immediate consequence of rarain is that the rarig immediately petrifies, or otherwise agalmatates, the particular substance that it changes into varying by breed. Even if the agalmatation is later reversed and the creature restored to flesh, it will be a rarig no more, but an ordinary member of the species corresponding to whatever form it changed fully into. Desperate rarigs discontent with their lot may voluntarily change fully into one form in order to end their condition, perhaps having made arrangements with a confederate beforehand to undo the agalmatation. Most rarigs, however, prefer to remain rarigs, and even of those who don't, few are quite that temerous. For the most part, therefore, rarigs are careful never to fully change into one form or another.
This is not, in general, a matter on which the rarig must expend much concentration; they are accustomed enough to the partial change to be very unlikely to fully change by accident. Tales circulate of especially foolish rarigs who are tricked into fully taking on one form and therefore agalmatating, and probably some of these stories are true, but they are very much the exception to the rule. However, a rarig also suffers from the full effect of having a single form if whatever parts correspond to its other form are severed. A chodeer currently in a form fully human except for one cervine foot will immediately agalmatate if that foot is severed. This puts an effective limitation on just how small a part a rarig can feasibly allot to a form. While it may be possible in principle for a rarig to take on one form fully save for a single hair of its second form, it would be a tremendous risk, because if that one hair was lost, or even fell out on its own, that would be the end of it. Of course, different rarigs vary in just how close they're willing to skirt the line.
Though rarigs are particularly common in the cosmos of Usm (and linguistic evidence suggests that it is there that the word originated), they have been found on some worlds on other cosmoi as well. Of course, these rarigs of different cosmoi pertain to different strains, and may have significant differences from those of Usm, in powers and other properties. The properties described here apply to the Usman strain unless specified otherwise.
Breeds
Rarigs come in near endless variety, with almost any sort of corporeal creature potentially serving as primary or secondary form. Nevertheless, certainly some are more common than others. The most common (at least in most well-known worlds) are those of human primary form, collectively known as chogatach (often clipped to "chog"). A chogatach of a specific secondary form is now most frequently specified by "cho" followed by the secondary species. For instance, a rarig with the primary form of a human and the secondary form of a cat would be a chocat, and one with the primary form of a human and the secondary form of a shark would be a choshark. Specific words for each form were formerly in use, and still are in some areas, but in most places have now fallen into desuetude, though some holdout magobiologists insist that they remain the more technically correct terms. In these somewhat antiquitated terms, a chocat was a chobotus, and a choshark a chotarra.
Rarigs of secondary human form are also not uncommon. These rarigs are sometimes called mallibons. For mallibons, the older terms for the different strains persist, though the final "o" of the older "cho" suffix is mostly apocopated (and inharmonious consonants at the ends of the first roots often elided); a rarig with a feline primary form and a human secondary would, for instance, be called a bottoch; one with a selachian primary and a human secondary, a tarrach.
Rarely, a rarig may have a primary and secondary form of the same species—but perhaps of different genders or ethnicities (or perhaps not). Such a rarig is called a chachalock. Where both the primary and secondary form are human, it's called a babosach. Occurring much more often among chachalocks than other rarigs, but quite rare even among the former, is the case in which each form essentially has a separate personality and a separate soul, and that while neither is ever entirely in control, the closer the rarig is to one form the more dominant the soul corresponding to that form. A rarig with this characteristic is known as a roachi.
Rarigs also infrequently occur with multiple secondary forms, called mapangatch. While these rarigs may have more options in their transformations, they are hampered by the fact that in each form they must keep features of each of their other forms. A mapangatch that neglects to maintain a feature of one of its forms, however, loses that form but does not undergo rarain as long as it retains at least two forms represented.
Powers
Many rarigs have other special powers and abilities aside from their transformations. One possessed by the rarigs of Usm (and perhaps by some other strains) is longevity; while rarigs are not generally immortal, they do tend to live at least four times as long as either their primary or secondary species. Rarigs also seem to have exceptional powers of healing and recuperation, in some strains including regeneration of damage that should have killed them several times over (though the rarigs of Usm aren't quite that hardy). This does not necessarily apply only to the rarigs themselves; the saliva of many rarigs seems to have healing properties that help to knit the wounds and soothe the injuries of others as well. (In the case of rarigs with forms that lack saliva, other bodily fluids may have similar properties.)
Rarigs also seem to commonly have exceptional acrobatic abilities, able to leap farther and move more quickly than either of their forms is capable of, and even able to scramble up sheer surfaces that seem to afford no foothold. Some rarigs can even walk upside-down on ceilings, though it seems that this particular ability is one that must be developed. Again, these abilities are not necessarily common to all strains of rarig, but do characterize those of Usm. Powers that have been not been observed in rarigs of Usm but have been seen in other strains include penetrating vision, agalmatation (of other entities, not counting the self-agalmatation of rarein), and short-distance translocation.
Weaknesses
Aside from the danger of rarein, rarigs have a particular vulnerability to blood of their secondary species. Contact with such blood not only causes a burning sensation (though without actually damaging the rarig's flesh), but causes the affected part to change to its other form against the rarig's will. If the part that came in contact with the blood was the only part to have one of the rarig's forms, and the blood therefore forces the rarig into a single form, then this change will result in rarein. If it acts quickly enough, however, a rarig so affected may be able to avoid this fate by changing another part to compensate.
Reproduction
Rarigs of the same primary and secondary forms can reproduce normally, according to the usual reproductive means of their corresponding species. Some strains of rarig are unable to transform while pregnant, remaining fixed in whatever form they were in at conception until they give birth, but this is not true of the most common Usman strain. The forebearance from changing entirely into one form seems to be largely instinctive, so even juvenile rarigs with no understanding of the consequences of rarein almost never fully take on one form by mistake. Most rarig strains can also reproduce with creatures of their primary or secondary species, the offspring generally being a rarig like their parent. (Reproduction between two rarigs of the same primary but different secondary forms, or vice versa, is also possible, usually resulting in a rarig like one of the parents (which one apparently random), but about five percent of the time in a mapangatch combining the forms of both.)
Conventional reproduction is not, however, the only means by which rarigs can increase in number. As the blood of their secondary creatures has a metamorphotic effect on rarigs, so too does the blood of a rarig have an effect on their primary creature. Even in small quantities, rarig blood burns their primary creatures as the blood of their secondary creatures does rarigs—again, doing no physical damage, but causing considerable pain. In sufficient quantities, however, the blood not only hurts the primary creature, but actually makes it into a rarig itself, of the same secondary creature as the blood's origin. The part of the creature in contact with the blood transforms into the new rarig's secondary form. The amount of blood necessary to effect this conversive reproduction seems to vary circumstantially, and the exact factors involved are not well understood, but it seems to be necessary for the blood to cover at least five or ten percent of the subject's surface.
Culture
Many rarigs disguise themselves as members of their primary or secondary forms, concealing their incongruous features and passing as ordinary beings of the corresponding species. Both chogatach and mallibons, for example, may live for long periods undetected in human communities—though their longevity marks them if they stay in one place too long. Sometimes rarigs form their own insular subcultures within their surrounding communities, but other times they do their best to integrate themselves completely, living as their primary or secondary species as much as possible.
Other rarigs, however, prefer to live by themselves, disdaining the company of creatures corresponding to either of their forms. Where rarigs are rare and the gathering of large numbers is impractical, such rarigs have little choice but to become loners, or to join up with a community of some other species different from either of its forms. Where they are more common, however, entire communities of rarigs may spring up, with their own customs and cultures completely different from either of their forms and drawing on the rarigs' distinct abilities and characteristics.