The cubi (singular cubus) are an unusual offshoot of humanity. It’s not clear whether they are a subspecies or just humans with a congenital condition, but they have been around for thousands of years, and are reflected in myths as the incubus and succubus, among others. Indeed, the name “cubus” is derived from those two mythological creatures, though cubi are not demons like the myths claim.
Cubi are physically indistinguishable from humans. Though they are generally reported as being more attractive than other humans, actual studies do not support this view. Cubi are almost as diverse as the wider human race, though dwarvish cubi have yet to be attested.
A cubus is always born female from a normal human woman and an incubus father. Since the father reverts to female form after conception, a succubus is generally brought up without knowledge of their heritage.
Their true nature starts to become apparent around the onset of puberty, when intense feelings of attraction surface. Partly because of this, an estimated 60% of succubi become sexually active before the age of twenty.
Cubi are unable to reproduce between themselves. A cubi’s reproductive cycle is parasitic, mixing DNA from three parents rather than just two. A succubus receives sperm from a male parent and modifies it, mixing in their own DNA. Then, as an incubus, they pass it on to a female parent.
Cubi eat the same things as humans.
Under certain conditions, cubi undergo metamorphosis which changes their apparent physical gender characteristics. They cannot control this, though they can through force of will hold off the impending transformation, for example to ensure they are alone when it occurs. The transformation is triggered by sexual intercourse, and works both ways. Once the transformation begins, it takes between one and two hours to complete.
Cubi also produce pheromones in their sweat that slightly fog the mind of the opposite gender, reducing certain inhibitions; the effect is far subtler than most people think, though. They can learn to exercise some control over these pheromones, and dressing in thicker clothing that exposes less skin also reduces the effect. Though the pheromones have no distinct odour to a normal human nose, a cubi can recognize the scent, allowing them to identify others of their kind. They are not affected by the pheromones themselves, regardless of their current form.
In addition, cubi experience unusually intense feelings of attraction towards the opposite sex, relative to their current form. These feelings are more intense in male form than in female form. There is no such thing as a homosexual or asexual cubus, but bisexual ones do exist – in fact, nearly 30% of cubi experience attraction to both sexes in both forms.
Cubi also do not put on weight easily. This is probably at least partially responsible for the stereotype of cubi being more attractive; the pheromones likely also play a role in this.
Society and Culture
Cubi hide within a human society that largely shuns them, due in large part to a history of rapes perpetrated by their kind, especially in male form (though in fact only about 30% of cubi have raped a woman; most manage to exercise more control over their urges, and most that don’t end up regretting the lapse). The magical society in particular dislikes them – the Ministry of Magic, for example, defines them as a “dangerous species”, and the Alpine elf kingdom, one of the few not to outwardly persecute them, still looks down on as cursed beings. About three in every million humans are cubi, though Europe and North America both have a proportionally higher concentration of them.
Once a cubus discovers what they are, even if they don’t have a name for it, many cubi are ashamed and do their best to hide it from their friends and family. The suicide rate among cubi is quite high. According to a 2011 survey by the University of Atlantis, there were 1,067 cubus suicides in the UK, of which 536 killed themselves while in male form. The official 2011 UK suicide statistics from the government reported 4,552 male suicides and 1,493 female suicides; although these numbers miss quite a few cubus suicides, it still shows that around 35% of female suicides in the UK are actually succubi, while about 12% of male suicides are incubi. The total cubus population in the UK is estimated at 2,842,500, giving a suicide rate of around three times the reported suicide rate for humans (which also includes cubi). The study also covered the USA, where the situation is even worse – the estimated cubus suicide rate is seven times the reported human suicide rate.
Occasionally, a cubus can go their entire life without learning of their condition, if they manage to get control over their pheremones and feelings enough to remain celibate. It is unknown how common this is, as such cubi may not be reflected in studies of their population. According to researchers at Atlantis University, there have been two or three reports of such cubi per decade, but it’s possible that many more go undetected.
Since the early sixteenth century there has been an underground community, centered in eastern France and partially organized by the elves living in the area, which is dedicated to helping cubi to deal with their condition. For most of its lifetime, this community was fragmented across Europe and parts of North America, but in recent years it has been brought together by the Internet. This has allowed many cubi to realize that they are not unique, and some are even starting to question the common view of their condition as a curse.
Cubi were the result of illegal genetic engineering experiments in ancient Atlantis around seven thousand years ago. In particular, they were a failed attempt to create hermaphroditic humans. Though the researchers planned to dispose of their failed creations, the cubi got wind of this plan and managed to stage an escape. (A number of other unusual species were also produced by these experiments, some of which are even still extant.)
Since then, they’ve managed to blend into human society and spread all across the world, though they are still most populous in Europe and second-most in North America as a result of colonization.
Since cubi tend to try to stay under the radar, there are few records of famous cubi. Even though there are legends of certain people (such as Merlin) being born of an incubus father, these are generally based on false rumour, not backed up by fact.