Dark Magic in the Bright Sun
There are very few documented, viable cross breeds in the world. Of them two stand out; Half-Elves and Half-Orcs.
Half-Elves are the natural offspring of elves and men. Exceedingly rare, and often sterile, these beings share traits from both parents. They are often taken in by one society or the other, though in more cosmopolitan areas, they experience a mix of all ways of life and easily integrate.
Half-Orcs are another story. They are not truly hybrids, but unfortunate throwbacks of dark magics of the past. It is rumored that orcs were created from man, and that the magic taint that created them still infects the world, altering men into orcs during dark phases if said magics are released.
Half-Orcs are believed to be a manifestation of that magic on the unborn. These creatures are more intelligent and more social than their Orc forebearers, but share with them the size, looks and skin tones more closely than they do their human parents.
Most are left out to die when born, and if they are raised by their parents or as foundlings they are often reviled and rarely accepted into society.