The Carnotaurs are vicious-looking, meat-eating dinosaurs with red scales, large tails, sharp teeth, and short horns. The two Carnotaurs that serve as the film's main antagonists are noticeably different in size, though it is unknown whether they are a mated pair or just relatives, nor are their genders known.
Not necessarily evil, they are predators who need food and water to survive. This is the main reason for the confrontation in the film; they have no real malicious intent. They just care about feeding themselves and only show respect for themselves and no one else. However, they are somewhat smart, as they follow the clan to find water. The two in the movie might be a mated pair or just relatives, but they have a very strong bond and the surviving one shows a powerful grudge against Aladar, trying to drag him over a cliff even when it was obvious the Carnotaur would die, after the other one was crushed by rocks Aladar's friends caused to fall on it.
Even so, they are extremely vicious, dangerous, and feared, described as a "mouthful of teeth with a bad attitude" by Eema.
A Carnotaurus first appears in the very beginning of the film where a young Parasaurolophus chases a flying lizard into the jungle. It then looks up to where the reptile is, but before it can get close, saliva falls on the branch which caused the young dinosaur to look up where the Carnotaur eventually awakens. The young Parasaurolophus starts running out of the jungle which causes attention to many of the herbivorous dinosaurs. As it starts running, the Carnotaur soon bursts out of the trees and starts chasing all the dinosaurs, and eventually kills a Pachyrhinosaurus.
At the middle of the film, two Carnotaurus, the larger one presumbly the same one from the beginning of the movie, scare off a pack ofVelociraptors. The pair then go after the herd in which Aladar and his lemur family and dinosaur friends are in by following the tracks left behind.
A little later, Bruton and a scout are attacked by the Carnotaurus. Bruton escapes to warn Kron, albeit being injured, as the scout is killed by them. As soon as Bruton tells Kron, he is left behind to fend for himself.
Later as Aladar, his family and friends, and Bruton take shelter from a rainstorm in a cave, the Carnotaurs attack. Bruton comes to the rescue and sacrifices himself by causing a cave-in, killing the smaller Carnotaur, but the larger one survives, leaves and roars, apparently in rage at the loss of his companion.
After Aladar and company find the Nesting Grounds, Aladar rushes back to warn Kron's herd about the rock pile blocking the main entrance. On the way there, he see a dead dinosaur (Stygimoloch) and soon flees when he hears the Carnotaur coming and eating the Stygimoloch.
Aladar then warns Kron and the herd about the approaching Carnotaur, but Kron doesn't listen to him as he thinks he's leading him right to the herd. After his battle with Kron, Aladar assumes the herd's leadership, then the Carnotaur arrives and the herd panics. Aladar states that they should stand together, or he would pick them off, in which they do and the Carnotaur backs off. Then, he sees Kron and runs after him with Neera and Aladar not far behind. After Kron climbs the rocks and finds a cliff, the Carnotaur corners him. Kron fights back, but the Carnotaur bites him in the back and tosses him against a rock. As he is about to finish him off, Neera comes and shoves the Carnotaur in an attempt to save her brother, but is easily overwhelmed. Then when the Carnotaur was about to kill Neera, Aladar arrives, and manages to push the Carnotaur to the edge of the cliff and the Carnotaur's weight causes the cliff ledge to crumble. As the cliff starts to crack, the Carnotaur grabs Aladar and tries to pull him down with him, but fails and the Carnotaur falls off the cliff to his death.
- In Dinosaur, Carnotaurus was shown to be much bigger than it was in real life. The film shows it to be at least as big, if not bigger, than Tyrannosaurus Rex. In actuality, Carnotaurus was smaller; about 10-13 feet tall and 26 feet long (while Tyrannosaurus was 15-20 feet tall and 40 feet in length), thus making it smaller than Iguanodon, the main dinosaur of the movie.
- According to the behind-the-scenes features on the DVD, the Carnotaurus is at least 15 feet tall in the movie.
- During the production of DINOSAUR, original plans called for the famous Tyrannosaurus Rex, but Disney decided to incorporate the lesser but popular Carnotaurus instead, resembling the devilish appearance as the primary antagonist.
- The canyon scenes were possibly set in the Americas because Carnotaurus and several iguanodonts (not Iguanodon) were discovered in Argentina. The death spots of the two abelisaurids were in South America and the rest of the film most likely takes place in North America (the nesting grounds), Asia (the desert), and Europe (the original nesting ground/land).
- Many fans and viewers often mistake the Carnotaurus portrayed in the film as T-Rex due to their large size. They even nearly resemble a devil-like T-Rex in appearance.
- The vocal effects for the Carnotaurus were based on the roars of big cats.
- The 2nd Carnotaur was perhaps the larger one's mate, sibling or twin.
- The Carnotaurs encountered Winnie the Pooh and his friends in Pooh's Adventures of Dinosaur.
- The Carnotaurs encountered SpongeBob and his friends in SpongeBob and Friends Meet Dinosaur.
- The Carnotaurs encountered Littlefoot and his friends in Littlefoot's Adventures of Dinosaur.
- The Carnotaurs encountered Tino and his friends in Weekenders Adventures of Dinosaur.
- The Carnotaurs encountered Thomas the Tank Engine and his friends in Thomas' Adventures of Dinosaur.
- The Carnotaurs encountered the FT Squad in The FT Squad's Adventures in Dinosaur, where they allied themselves with Greedon and Gold Claw.
- The Carnotautus encountered Team Griffin/Eeveelution and their friends in Brian and the Eeveelution Family's Adventures of Dinosaur.
- Roger Smith prefers the Carnotaurs as "The Devilsaurus Rex".