Tiefling

Humans with demonic ancestry, whose lineage can be traced back to some degree or another to that of a fiend or demon, whereas the demonic lineage lies far up the family tree.
http://forgottenrealms.wikia.com/wiki/Tiefling
In the modern world all species have cross-bred to the point that a wild amount of variance exists. Because of this many height, age, and size extremes have been normalized closer to the average human lifespan. This species selection marks the dominant visual influence.

Basic Information

Anatomy

While some looked like normal humans, most retained physical characteristics derived from their ancestor, with the most common such features being horns, prehensile tails, and pointed teeth. Some tieflings also had eyes that were solid orbs of black, red, white, silver, or gold, while others had eyes more similar to those of humans.[11] Other, more unusual characteristics included a sulfurous odor, cloven feet, or a general aura of discomfort they left on others.

Biological Traits

In many other ways, tieflings were similar to humans physically. Tieflings were, on average, just as tall as humans, from 5'6" – 6'2" (1.67 – 1.88 m) and weighed just a little bit heavier at 140 – 220 lbs (64 – 91 kg). Tiefling skin was usually human-like in color, though extending past normal human colors into reddish hues as well. Tiefling hair was also often the same color as human hair, though dark blue, red, or purple were common shades amongst the race