Biology breakdown: Giants

Giants are humanoid beings, featuring the same fundamental components common to humans. Obviously, they differentiate themselves from the other primate species through their enormous size and certain additional features unique to them. This is possible because early in the development of primate species, a common ancestor of humans, giants and vull'jorgs branched off into several distinct paths, with the giant's ancestor veering into gigantism, far exceeding its competition in mass and bulk as it acquired food more easily in the regions it was located.
  While this increased size naturally meant greater physical strength and less threat from predation, it also came with the caveat of increased upkeep to sustain such size, as well as the arguably far more pressing issue of over-heating, thereby restricting the habitable areas these ancient giants could live in. These two main issues are averted through giants developing a more lethargic approach to life, spending as much as two-thirds of their time asleep to conserve energy, in addition to living in the cooler regions of Az such as the northern and southern poles and various temperate mountain ranges and hills, avoiding deserts and tropical regions if at all possible.
  Despite these limitations, there have been several observed sub-categories of giant by the time of developed writing systems; the most prolific variant being the Cold giants, who in turn are made up of the Mik-Rhulak, Frynnish, Southern and the giants found on Shutontas, all of which feature thick hair around much of the body and greater size then their counterparts, the Warm giants. Warm giants are a decidedly rarer group of beings, in no small part as a result of their biology hampering their ability to settle in warmer regions.
  Amongst them are the now extinct Fire giants, whose grey skin and gigantic ears lent to their name as the Elephant Men by people on Yddian, the cause of their disappearance largely attributed to the genocides facilitated by the Vull'jorg and an inability to compete with humans they were in contact with. They are joined by the giants of the Massidian empire, who were once considered a part of the cold giants, akin to the Frynnish, but after enslavement by the Massidians were forced to adapt to their new habitat through a combination of selective breeding and alterations through magical means.
  However, there also supposedly exists the Typhoon Giants, also known as Rafters, an elusive group who wander the oceans of Az on great structures fashioned from mangrove logs and seaweed, addressing their dietary needs with a steady supply of fish and sea-plants. What makes the Typhoon giants remarkable is their apparent ease at which they can swim and dive through water, a trait that most giants struggle to acquire if not find outright impossible. This is most likely a result of the oily diets and less dense bodies these sea giants are accustomed to.
  As a final note, common features shared amongst all giants is their proportionately large ears adapted as a coolant measure and enhancement to their auditory senses, wider skeletal build and several small organs and muscle groups not found in humans such as an additional layering of muscles around the neck, abdomen and thoracic girdle in order to keep their bodies upheld.