As a half-orc character, you've grown up more accustomed to your human parent's community than your orcish one (though perhaps you have an interesting story or two from that side of the family).

The civilized lands within a few days of Ptolus have provided more opportunities than the outlands -- your size and brawn brought options. Perhaps you have worked as a laborer on a farm, or as a mercenary soldier. If you can swim, perhaps you served on a ship. Maybe you were even part of the guard of a small keep.

Coming to Ptolus proper, you know you will get fewer strange looks than elsewhere -- people there are used to the strange and unusual. Though no matter where you live, your appearance will never work in your favor. But you could seek your fortune in Ptolus, and change your life entirely. Or perhaps you wish to someday join the City Watch, or just serve your god through glory and combat. You know there are those in Ptolus who have overcome their ill-birth and made a name for themselves, and that may be your goal.