The T-Rexes are antagonists created by youtuber Hoopsanddinoman, they are predators that live in Nightmare Canyon. Their primary aim is to kill and eat any dinosaur to go through Nightmare Canyon. Noasaurus was looking for food until a large Male Tyrannosaurus Rex appeared and chased him up a hill side, then a large Female Tyrannosaurus Rex chased Noasaurus through a rock maze, Noasaurus however teleported through the maze, tricking the Female, he then knocked over the rocks, even knocking the Female onto the Male, Noasaurus also threw rocks on the T-Rexes and walked away, the next time they appeared, they attacked Noasaurus, but this time Stegosaurus swung from a vine and hit them, knocking them over, then Carcharodontosaurus attacked them along with Stegosaurus, after they brought Dimetrodon back to normal, the Male attacked Saltasaurus and tried to eat him, but Diplocaulus and Dimetrodon saved him, and then they went up the tunnel, but the Male fallowed them up it, then Ultrasaurus took him on in an epic battle, Ultrasaurus knocked the Male off the cliff, but the Male grabbed his tail, so the two of them fell to their deaths, the next time the Female appeared, she attacked the Red Ceratosaurus, but Allosaurus threw a teleporter at her and sliced her neck, leaving a scar, so the two of them went back to herd, after meeting Pteranodon, Saltasaurus got attacked by the Female, but his friend Ceratosaurus came in to fight the Female off, Saltasaurus watched the battle, Ceratosaurus tackled the T-Rex to the ground and snapped her jaws, forcing her to get back up, Ceratosaurus then jumped at her and hit her side so hard, killing her.