Great Horned One is an adult Carnotaurus with dark gray skin, a pair of short horns on her rather stubby head, and somewhat useless short arms. Her overall description, along with her size, somewhat resembles a T-Rex.
According to Nashoba, Great Horned One, as with her brethren, is a predator who kills because that is what they was made for. Indeed, while her first on-screen appearance established her as instinctive yet ferocious beasts, she lacked true malice compared to other film's antagonists, and more of a neutral being with virtuous and compassionate qualities; the Carnotaurus’ maternal side was shown when she brings an injured wild boat to her two broods to feed on. Later, when she was forced by Turok to help him saving Cliff People from Chicak and his army of Cave Dwellers, Great Horned One developed a degree of begrudging respect towards the human despite her initial anger — apparently understanding his motives (protecting his friends as much as she does to her children), the Carnotaurus opted to chase the demoralized Cave Dwellers instead.
Role in the Storyline
Encounter With Turok and co.
The Great Horned One's first onscreen appearance was when she caused a herd of Ankylosauruses to run before setting her sight upon Chichak and Catori whom she perceived as easy preys. But then Turok and Andar come to their rescue where the ensuing fight forced Chichak to retreat, all while escaping the Carnotaurus’ grasp. Watching them eacaping at the waterfall, she loses her interest and hunts somewhere else.
Feeding Her Brood
Sometime later, Great Horned One managed to catch a wild boar and feeds them to her young. While making her leave for her own meals, she was oblivious to Turok's presence when he stumbled upon her nest as he tracks down Cave Dwellers, let alone noticing him as they come close to croos-paths near Cave Dwellers' hideout (since its inhabitants knocked Turok out before it happens).
"From Blood Follows Blood"
Knowing that they need more help they can get to save Cliff People from Chichak and his Cave Dweller minions, Turok devised a plan to make it a fair fight. Using his blood, the unsuspecting Great Horned One comes for him only for Turok subdue her like a horse with a spear tied with a rope as reins, taming the Carnotaurus. Though not pleased with this, she nevertheless aid the humans rescuing their people.
As Turok and Chichak's duel concluded with the latter got decapitated by the former, Great Horned One stomps Chichak's severed head to confront Turok in his place. Silence rippled among both sides with lighting flashes on the background. For quite sometime the unlikely allies stared on each other as if they are communicating, before the Carnotaurus opted to chase away the fleeing Cave Dwellers.
It's unknown what happened to the Carnotaurus afterwards, but considering Cave Dwellers greatly feared her and worse, have reduced into broken people following the loss of their leader, it can be inferred that Great Horned One had slaughtered at least scores of them and spared the rest before they could fight back.