Orcs (Kings of War)
In Kings of War the orcs were created by the Wicked Ones Garkhan the Black and Dark Kyron. Whereas most of Oskan's allies sought to corrupt existing races to serve their ends, Garkhan felt that if he wanted a race bred for war, he should just make one. Much like in Tolkien, his race lives only to spread itself out and fight, not giving much thought to forming nations or clans. Instead orcs fight under warlords or Wicked Ones until such individuals are defeated, at which point they flee only to repeat the process once again when a new master comes calling.
Gakamak the Smasher
An infamous orc warlord known throughout northern Mantica. He is said to have faced elven drakon knights in battle numerous times, as well as battling the Abyssal demon known as the Lord of Midnight and surviving. The orc "mega army" bundle sold by Mantic is said to be his horde.
Final boss of the Dungeon Saga quest module "Warlord of Galahir." Thrundak Skullsplitter is an orc barbarian who leads a large war band composed of orcs, goblins, and trolls. He has raided the Forest of Galahir periodically for years. In the module his war band is pursued by Hrrath Flamespitter and Kapoka, along with their allies, and eventually defeated by them. Currently the only orc hero to have his own model.
Wip the Half-Cast
Wip the Half-Cast is a harebrained orc godspeaker who has a strange commanding presence about him to younger orcs. Though smaller and weaker than most orcs, Wip found he had a solid command over magic and was much more agile then the average orc, leading to rumors he might not actually be an orc at all. Everywhere he goes he is accompanied by his "affectionate playmates and adorers," represented on the tabletop as orclings.
On the Tabletop
Tactics can be found here: Kings of War/Tactics/Orcs
Orcs are a mid-range army, possessing middle of the road units of most every type.