The Gates of Hell
Since the opening of the Hell Gates, many different beings have taken residence on the planet. Some of them have even bred into the human bloodline, resulting in creatures that resemble humans more than anything else, but that may possess strange powers. The most powerful of those humanoids will grow to take on the appearance of their bloodline.
By and large the most common of any of the races, humanity still dominates what is left of civilization. Most humans are blissful unaware of the other races; even many of the races believe themselves to be humans who are simply colored differently!
The Church claims these creatures are demons, though the creatures themselves claim this is a lie. There are many different kinds of lycans, including werebears, wererats, weretigers and the most common, werewolves.
Lycans appear as normal humans, though often they will give themselves a bestial nature such as wearing only furs or letting their hair grow untaimed. When they shift into their animal form they take on the appearance of a normal animal of that kind.
Tieflings are the result of demonic meddling with human bloodlines. This could be as far as several generations, or a direct parent. Tieflings appear as dark skinned individuals with small bony lumps on their heads.
While the dragons came to Earth in the same means as the demons and angels, their blood constitutes something much different from human blood. This is proven by the existence of the dragonborn; humans with dragonic blood in them. Dragonborn tend to be much larger than typical humans, with small leathery lumps of skin randomly on their bodies and on their backs; where wings would protrude if they were full-blooded dragons. They are typically compelled to fight by their dragonic heritage, and you will find dragonborn in armies and as wondering adventurers the world over.
Eladrin are humans of angelic descent. They possess incredibly smooth and beautiful features, like a porcelain doll maker had crafted their bodies. Eladrin are gifted with an ability to teleport short distances and only require four hours of deep meditation a night; although many Eladrin deny their abilities and insist on sleeping like a normal person, they do not truly need it.
This is the least common of any of the races, at least partially because angels are the least inclined to sleep with a human. Eladrin typically take on the angelic mindset, being very straightforward about business and attacking their goals head on.