Half breeds and a Human
“While most half-breeds have little place in the world, those born of humans and orcs are the worst, a bastard of race and creed; bred by savages doing savage things only to make more savages.” Sir Gillid, Knight of the Southern Kingdom
The first generation of half-orcs does not normally come from a peaceful act, and by in large the mother is usually human. That being said, some of the Northern orc clans live relatively close and peaceful to some small human settlements and it is rare but not unheard of for some tribes to get close with these humans.
The most notworthy piece is that, no matter how the child was conceived they will almost exclusively be brought up by the orc clan as young ones with orc blood are to much for even the most tempered of women to raise. While nothing in the clan says they are less, these half-orcs will face a good amount of prejudice and find that they have to prove themselves above and beyond that of the regular orcs.