Creatures of Atharon
Although most of the world has been explored and mapped out, humans claim only half of the inhabitable areas, mostly occupying large valleys, river shores and coastlines, relying on their strength in numbers and their structures for safety. The rest of the habitable world, the forests, the swamps, the mountain regions and numerous inhospitable areas; they all belong to nature, to her creations and her creatures. Many of the creatures came into existence long before the humans did, as a result of the Sentinels attempts to gain control over the elements, the building blocks of the mortal world. Those that came into existence after the Sentinels perished only did so through spontaneous convergence of unforeseen circumstances.
The creatures of Atharon can be divided into three distinctive categories: Instinctive, Sub-Sentient and Sentient.
The instinctive creatures lack any significant thought process and function on highly developed instincts. Most of them are common beasts, such as bears, wolves, lions, sabertooths (''Sabers'' in short) on land, mostly residing deep within thick forests or high upon the mountains, and in the less hospitable regions humans were unable to claim as their own. Other instinctives live in seas as various form of fish, from the smallest sardines (the size of a human finger) up to the largest behemoths (the size of a ship and even larger). Then there are those who claimed the skies, from the tiny sparrows up to the largest eagles. Many of them appeared long before the humans did, but some that came later are supposed to have been created by the Sentinels to satisfy the humans; those were intended as prey for the humans, although many of them have been domesticated for multiple purposes.
The sub-sentient species were mostly created by the Sentinels in a time before the humans. They were provided with a limited form of sentience in order to be able to understand and carry out the Sentinels orders. The earliest of these beings were several species of Dragons, each of them granted the ability to command a single element. Unfortunately, the Dragons themselves were rigid and lacked the capacity to adapt and evolve, but since the Sentinels were more concerned about progress than anything else, they allowed them to become extinct. The further the Sentinels went with their experiments, the more species they made, mixing them up and creating random combinations, from the Mermaids who innocently reside in seas up to the Harpies who relentlessly ravage the lands. The sub-sentients that came into existence after the Sentinels have perished did so only through a combination of unforeseen consequences when a human dies and releases his soul in a significantly weakened state. Since the soul is unable to reach the purgatory, it lingers within the real world and takes various shapes after it loses sense of itself (and loses enough of it's sentience to ''devolve''). For example, Banshees, Sirens and Wraiths are only some of the creatures created this way depending on the circumstances. These sub-sentients manifest themselves both in physical and mental aspects, meaning they cannot be seriously harmed by strictly physical or mental attacks, only seriously pissed off. Although they mostly appear alone, they are considered extremely dangerous since they have to feed on human souls in order to survive. Fortunately, all combat professions possess the needed skills to tackle the mental aspect as well as the physical, therefore most highly-trained fighters are capable of fending off these creatures.
The sentient species, the humans in particular, were created as the absolute pinnacle of Sentinel ingenuity. Combining all the best features of all the sub-sentients that came before them, the humans were instantly able to understand and shape the world in a much better way than any other species. Due to their highly developed self-awareness, sentience, they were considerably more devoted to accomplishing the Sentinels goals rather than their own, at least in the beginning, and carried out everything the Sentinels ordered down to a letter, unlike the sub-sentients who did so only out of convenience. It is the very reason why the Sentinels decided to grant them the prestige to reside along with them in the Spiritual world. The rest is history, slowly but surely the humans eradicated pretty much everything they considered a threat and set themselves up as the dominant species on both worlds.
(It is important to note that the humans are the ONLY sentients created by the Sentinels themselves. Other sentients that exist today achieved their sentient status through the natural course of evolution from their sub-sentient forms, such as the Kobolds, for example.)