There’s a powerful and ancient civilization in the Gods of Terra setting, descendants of terrestrial prehumanity , and belonging to their own hominin genus: Meganthropus tokmolosensis, the gigantic Mokthraga, and a somewhat shorter species, Meganthropus mentis, the Miithrok, both looking something like massively-built, impossibly tall and well-muscled humans.
Mokthraga average about 4 meters tall and mass an average of 800 kilograms; Miithrok average 3 meters tall and mass about 450 kg, not exactly beings you want to get angry with you. The frightening thing is that these are not low gravity species, but natives of a 1.3 gravity world, rich even in the planetary crust and oceans with heavy metal concentrations toxic to Terran life, but exotic only in this regard – most life is still carbon-based, just with a higher tolerance for heavy metals, particularly titanium, which takes the place of calcium in the bones of most vertebrate analogs, and the exoskeletons and shells of invertebrates, for example, the local analogs of beetles and molluskoids.
This, and factors of the Giants’ anatomy deviating from the human baseline are what make them possible, keeping them from collapsing of their own weight due to the implications of the square/cube law.
First, it’s almost impossible to mistake them for humans in good lighting, even at a distance. They don’t look exactly human in proportion. They’re too broad in build. Think of the incredible Hulk, then scale that up a bit. The Giants are literally built to support their mass, using titanium in their skeletons in place of the calcium that their ancestors used before the ‘Great Experiment’ of the Strangers, an unidentified, hypothetical civilization with a penchant for biological meddling that resulted in the divergent evolution of transplanted human offshoot populations on dozens of worlds.
The bones, muscles and the connective tissues of the Giants, including cardiac muscle, ligaments and tendons, are all thicker and denser, with much more tensile strength than those of baseline humans, adding to their massive builds and giving them the tremendous strength they need to live comfortably in their native gravity.
This helped keep them from suffering more than their due from the medical problems related to heavy gravity living. That, in turn, relieved selective pressures toward a reduction in size and mass exceeding that of the Miithrok. At first, these were genetically engineered into them by the Strangers, in giving them the necessary adaptations for survival on their home, and these were built upon by natural selection once the population was fully transplanted and underwent breeding.
Whatever they were when first brought to Tokmolos from ancient Earth, they are now so unlike us biologically that only their DNA and fundamental chemistry speaks of Terran ancestry. Even the foods they eat would be toxic to humans, which makes setting up interspecies restaurants difficult – food items must be labelled for edibility by species, as some Tokmolosian delicacies are poisonous to beings such as humans.
As I said, they’re an old race for one descended from early Terran hominins, becoming a technological civilization about 50 millennia ago, brought to Tokmolos as live specimens and genetic samples much earlier before the rise of anatomically modern Homo sapiens.
The Giants have a conservative streak; not in the political or ideological sense, of course, but they’ve grown old as a species and are slow to change. There is a certain degree of contentment in the now, with a patience and tolerance of difference that makes them amiable enough with other beings, but slow to react to threats. They are no longer as curious as they were in their youth as a species, when much of their scientific and technological innovation occurred. Oh, they still do science, but not as much.
They’ve turned inward, and stopped looking at the universe outside their sphere of colony worlds, systems cut off from contact by massive Dyson spheres and Cryswell structures built around their stars.
This could mean their end, despite their status as a Kardashev scale Type II civilization. A young and aggressive race, the Kai’Siri, are encroaching on their ancient borders, and have discovered a frightful new weapon to counter the powerful but archaic technology of the Giants: Humans, or something very much like them, ‘Wavetouched,’ implanted with the powerful quasi-matter hypershard relics; weaponized soldiers empowered to single-handedly cause planetary extinction-level events.
Will the Children of Tokmolos survive? Or will their Elder civilization be wiped from the skies forever by enslaved doomsday weapons that kill every world they’ve ever been sent against?
We’ll see…Time and luck are of the essence.