The forest of Taur-i-Thorogrim, or 'Forest of troll-men' in Sindarin, is a cursed forest on the borders of Perdorogwaith. It is a part of the larger Far Harad Forest, but it is under the control of the Half-trolls of Perdorogwaith and cursed by ancient atrocities. The region centres around the river Seregduin, which flows from the southernmost of the Great Lakes of Harad in the through the Far Harad Forest and into Perdorogwaith.
In the late Second Age, this region was the heartland of the Empire of Kimen Kâh, the last true kingdom of the Taurethrim. But that changed in SA 2161, when an army of Half-trolls crushed the armies of the Taurethrim in a terrible battle at the borders of the woods, and then besieged and razed Kimen Kâh itself. The Half-trolls slaughtered the entire population of the city, and the dead were so numerous that the river near which the city was built ran red with blood, for which reason it was named the Seregduin. This horrible massacre left the Taur-i-Thorogrim cursed, and the region has been under the rule of Half-troll tribes ever since.
Compared to the surrounding forest, which is green and full of life, the Taur-i-Thorogrim is a dying land. As with the Far Harad Forest, the biome is dominated by oak and acacia trees, but many of them are dead, and other vegetation is sparser. The grass is much greyer here than it is in the surrounding forest, and the sky is a similar shade of greyish-brown. Boulders, piles of waste, and skulls from the ancient massacre dot the forest. Taur-i-Thorogrim is constantly shrouded in a thick layer of fog.
This region is dominated by the Man-hating Half-trolls, who ensure that traders and Bandits alike stay away. Their warriors occasionally patrol the biome, and larger groups of them invade the region as well. The Taurethrim send out incidental expeditions to this forest, likely seeking to drive the Grey Demons that they hate so much from the ruins of one of their old kingdoms.
Upon entering this region, the player is granted the achievement "Forest of Demons".
Next to the standard, most common, variant, the following biome variants can be found here:
- Flowers - A version of the biome with an abundance of flowers.
- Light Forest - A lightly forested version of the biome, has a bit more trees than the standard version.
- Hills - A hillier version of the biome.
- Forest Hills - A forested version of the hill variant.
- Clearing - Areas where trees are less abundant than in the surrounding lands, but the soil is not particularly poorer.
- Wasteland - Wasteland is a very barren biome and can vast stretches of the terrain consist of barren rock. The soil is generally very poor and vegetation is sparse. The landscape can both consist of flat plains and rolling hills.
Apart from scattered ruins of what seem to have been Taurethrim constructs, there are no structures in this region. The Half-trolls passing through the forest have no need for permanent structures with Perdorogwaith nearby, and so they have built nothing here, not even camps.
The Taur-i-Thorogrim is under the control of the Half-trolls of Perdorogwaith, and though they do not live here, their warriors do patrol the biome. As in Perdorogwaith, the Half-trolls have driven many species to extinction in this region, and only a handful of animal species can be encountered here.
- Half-troll - Vicious, inhuman savages that look like a mix of Men and Trolls. They are larger than the player and have dark skin, animal-like tusks and horns, and are without weapons or armour, wearing only minimal, raggedy clothes.
- Half-troll Warrior - Warriors of the Half-trolls. Unlike their civilian brethren, they wear Half-troll armour and wield Half-troll weapons, which includes scimitars, daggers, pikes, warhammers, maces, and battleaxes. They have no ranged variant.
- Half-troll Scavenger - Unusual traders that spawn randomly in small groups. They sell odds and ends to the weary traveller, and buy odds and ends in turn. Unlike every other trader, they will attack anyone with negative Half-troll alignment with their poisoned daggers.
- Crocodile - Hostile mobs who live in the water and can also be on land. They are ferocious beasts. In daylight, they are quite slow, but a night, they are fast. They can swim faster than the player.
- Gemsbok - Passive antelope-like mobs. Their hide makes very nice looking armour.
- Rhino - Rideable mobs that can charge into battle. They are neutral.
As with every biome in Far Harad except Perdorogwaith, Taur-i-Thorogrim generates gemstones at a slightly higher rate than most biomes, akin to the rates at which they can be found in most mountain foothills, together with all of the usual ores.
Since the Half-trolls conquered the biome and it became cursed, Taur-i-Thorogrim has begun to lose its resemblance to the neighbouring Far Harad Forest. In terms of vegetation, it is very similar to a cross between Perdorogwaith and the Far Harad Forest, dominated by acacia trees and desert oaks, many of which are dead. Boulders or piles of waste blocks break up the forest fairly frequently. Ground vegetation includes wheat grass, thistles, and clovers. Giant Baobab trees can occasionally be found here as well.