The Olog-hai are a subspecies of Troll and one of the main types of enemies as well as one of the new classes introduced in Middle-earth: Shadow of War.
A significant difference between the Uruk and the Olog is the latter's larger size and distinct lack of pointy ears; rather the Olog's ears are small and less fleshed out. Another key difference is the lack of five digits on their feet. Therefore, they appear similar to Goblins, but larger in stature.
The Olog-hai inhabit everywhere from the Misty Mountains to Mordor, and, unlike their Troll precursors, are not turned to stone by the light of the sun. Their presence among the Orcs' ranks (Goblins/Uruks/Orcs) typically manifests as armored soldiers or enforcers for smaller groups. They also work closely as master engineers alongside the Orc subspecies known as Goblins, able to create deadly weapons and powerful equipment such as blasting powder. There exist cases of human-level intelligence, but the majority are more in favor of brawn over brains, and thus can be easily tricked. They often make use of Goblin-forged or scavenged armor, though most prefer not to wear clothes.
The Dark Lord Sauron has begun to breed Olog-hai for the coming war, serving many purposes as soldiers, guards, and escorts, with several earning their place among the Captains and Warchiefs. A few even manage to become powerful enough to be named Overlords of the fortresses dotting Mordor's landscape. They also provide support as siege beasts, shock troopers, and gate-smashers.
The Ologs' tone of skin is more various than that of the Uruks, being found in pale yellow, orange yellow, grey blue, stone grey, reddish-bluish white, or even pale white.
It is also cited that after the War of the Ring, all of the Olog-Hai were slain.
In The Black Speech, olog means "troll" and hai means "folk" so, a compound of these word results in the word "Troll-Folk."