Orcs

Orcs are a godmade species made by Rage, Imperial God of War and Slaughter. It is not exactly known where it happened, but a lot of his cultists (probably in several places at once) were spontaneously mutated into orcs... which, admittedly, they considered an honour.
Needless to say they aren't exactly all that peaceful and friendly, being naturally sculpted towards being a species of bloodthirsty warmongers. Then again, it's not like they can only fight and are merely bloodthirsty warmongers. They are disciplined (and strong) enough to be considered prime recruit material for Imperial Army.
Despite this, they are treated pretty much like ogres. They are seen as barbarians and mistrusted, unless they actually managed to prove themselves otherwise. Of course, with their pure physical strength and rather short tempers, actually saying mean things to them is rare.

Basic Information

Anatomy

Orcs are tall, naturally muscular and with bodies that can be only summed up as seriously manly. Which makes sense, because orcs are a one-gender race that lacks females. Their skin colour varies - they are born with light green skin, but it naturally darkens overtime, all the time to almost black (with only a dark green tint to that).

Genetics and Reproduction

Orcs can reproduce with females from most species. They can even avoid typical limits (like elven being limited to themselves and ogres), making them quite unique. It's achieved by the orcs carrying genetic material of both male and female variety.
Women of other species act only as incubator, though there are indications that at last some minor genetical elements are taken from mothers. It seems to be especially vulnerable to things concerning magic - they are guaranteed to inherit at least a fraction of their mothers' inborn mana and magical invulnerabilities and vulnerabilities.
Interestingly enough, the orcs normally aren't capable of impregnating anybody, despite being quite sexually active. Actually forcing themselves into fertility (which is pretty much a self-imposed heat) they require either a lot of sex, or a lot of adrenaline (either by hunting or fighting the war). Once achieved, this state lasts for at least a week or two, with every sex in that period ending with pretty much guaranteed pregnancy unless the target is infertile or during period.
The pregnancy lasts for seven to eight months. Generally the earlier it happens, the stronger the orc with exception of those born premature - seven months is absolutely perfect.

Dietary Needs and Habits

Orcs are carnivores. They eat meat. Mostly - they can partially replace it with other things (preferably fish, then mushrooms and finally normal plants) but sooner or later they will start feeling weaker and weaker. They also enjoy bear and strong alcohols, but are rather displeased by wine, especially if its diluted in water.
One of the greatest disagreements between the Imperium of Karadia and orcs is that they are rather fervent cannibals. Consumption of the enemies they defeated in battle is quite common (especially in large tribes that still adhere to their traditional culture, those that assimilated unto other cultures do not commit acts of cannibalism (though they still might feel urge to do that after particularly fervent battle).
Due to the way their culture works, they specifically target the enemies that proved their strength, especially if they were the ones that that defeated them.

Additional Information

Facial characteristics

Extended (and pretty stocky) lower jawbone. A lot of fangs. A bit wider noses and generally pretty 'barbaric' faces, near the end of what would be possible among some unfortunate humans (with exception of skin colour). Eyes commonly red or violet.

Perception and Sensory Capabilities

Orcs are pretty average on the field of perception, not very different than average humans.

Civilization and Culture

Beauty Ideals

Their beauty is strength. As long as you are a warrior and are tough, you might even be impossibly ugly and you'll still be respected and even have admirers. Of course, being actually pretty (in a mostly human way) is a very nice bonus to being strong.

Gender Ideals

As an all-male species it's pretty obvious thing that orcs are EXTREMELY patriarchal. Each orcish clan has females - of pretty much every possible species - but they aren't considered equal in any way. Quite the opposite - they are supposed to prepare meals, clean, serve their de facto owners (which makes people often refer to them as slave-wifes, since while they are officially wifes, their position is much lower than in Imperium) in bed and give birth to new, preferably strong, orcs.
Because of that, most of them are either former outlaws (given to orcs as punishment), or simple slaves. They are also at least some volunteers. While orcs do consider themselves superior, actually using their physical strength on those weaker (and, for them, women are automatically weaker) is something absolutely dishonorable and can end up with being killed on a spot. With exception of punishment seen appropriate by the whole clan.
What's more, giving birth to healthy children requires eating well and no heavy working, the pregnant 'wifes' are often almost absurdly pampered. Which makes the part with volunteers (especially from the poor or desperate) actually appealing to some, especially with most of orcs at least partially expanding this treatment to all wifes, regardless of their pregnancy..

Relationship Ideals

Overwhelming majority of orcs (the exception are those that were brought outside their traditional culture) are polygamist. The stronger the orc, the more slave-wifes he has. Those lowest in the clan often have none, which makes them sometimes leave to establish their own clans.

Average Technological Level

Frankly, it's hunter-gatherer level for most, though their slave-wifes often keep at least some level of agriculture (if only for themselves) and crafting rolling.

History

Orcs began with about one hundred thousands of Rage worshippers that, during the Dawn War, were spontaneously transformed into first orcs. Including their women, according to some records, but that's unconfirmed.
The chaotic times of war ended up scattering them throughout Karadia, and divided them into many tribes. That, in turn, were divided into many smaller clans. For example most of Visenian and Diretian orcs are descendants of the same tribe that splintered overtime into a hundred of clans (from ten to one hundred strong) mostly living on the edge of civilization. Where they can hunt, train, and improve themselves in combat with things inhabiting wilderness.
They used to be hunted, but overtime the Imperium got used to them and began having more 'civilized' approach. Today orcs are mostly accepted (but aside from those becoming adventurers or mercenaries they tend to stick to their own people), but still mistrusted. Their relations with nearest villages range from cold war to defensive and trade agreements.