We're Back! A Dinosaur's Story
The film opens with a trio of young bluebirds harassing their youngest sibling, Buster (Blaze Berdahl). As Buster leaves his family, he meets an intelligent orange T. rex named Rex (John Goodman) playing golf. He explains to Buster that he was once a ravaging dinosaur, and proceeds to tell his personal story.
In prehistoric times, Rex was a savage, frightening creature who terrorized smaller dinosaurs. But one night, he encounters a strange spacecraft and a small green alien-like creature named Vorb (Jay Leno). Vorb captures Rex and feeds him "Brain Grain", a special breakfast cereal that vastly increases Rex's intelligence. Rex is given his name and introduced to other dinosaurs that have been fed Brain Grain: A green Parasaurolophus named Dweeb (Charles Fleischer), a blue Triceratops named Woog (Rene LeVant), and a purple Pteranodon named Elsa (Felicity Kendal). They soon meet Captain Neweyes (Walter Cronkite), the inventor of Brain Grain and pilot of the spacecraft, who reveals his goal of allowing the children of the present time to see real dinosaurs, fulfilling their biggest wishes. He plans to take them to Dr. Julia Bleeb (Julia Child), who will guide them to the Museum of Natural History in New York City. He also warns them to avoid Professor Screweyes (Kenneth Mars), his insane brother.
Neweyes drops the dinosaurs off at the East River in 1993, but they fail to meet with Dr. Bleeb. Instead, they meet a young boy named Louie (Joey Shea), who plans on running away to join the circus. Louie agrees to help the dinosaurs. Louie soon encounters a girl named Cecilia, who is miserable with her life because of her neglectful parents. She agrees to run away with Louie and help the dinosaurs.
To prevent mass panic, Louie decides that the dinosaurs need to stay hidden during their journey to the Natural History Museum. He disguises them as floats in the Macy's Thanksgiving Day Parade. During the parade, Rex hears all the children wishing to see real dinosaurs, so he starts to sing "Roll Back the Rock (To the Dawn of Time)" (the movie's theme song). When he sees the Apatosaurus balloon coming out in the parade however, Rex mistakes it for being real and hand shakes it too tight with his claws, causing its air sealer to pop open. The balloon runs out of air and falls on the dinosaurs, who are otherwise unharmed. When the audience realizes that live dinosaurs are among them, they fly into a panic. The local authorities are called in to stop the dinosaurs.
As the dinosaurs lose the police, Louie and Cecilia venture to Central Park, where Professor Screweyes is running his "Eccentric Circus". Unaware of Screweyes' sinister nature, the children sign a contract to perform in his circus troupe. The dinosaurs arrive and try to prevent this, but they are too late. Screweyes, upon meeting the dinosaurs, explains that he delights in scaring people and believes that the dinosaurs would make a great addition to his circus. He then reveals his very own "Brain Drain", pills that are the polar opposite of his brother's Brain Grain. He demonstrates the Brain Drain on the two children, devolving them into chimpanzees; however, he offers the dinosaurs a deal: if they consume the pills and join his circus, he would destroy the contract and release Louie and Cecilia. Reluctantly and sadly, the dinosaurs accept the offer.
As the kids awake the next morning, they are greeted by a circus clown named Stubbs (Martin Short). Upon seeing the dinosaurs returned to their natural savage states, Louie and Cecilia, with the help of Stubbs, plan to sneak into the night's show and save the dinosaurs. Professor Screweyes claims he can control the now-savage Rex, and proceeds to hypnotize him. Everyone watching the show gets frightened during the performance, and many run away. However, a crow accidentally activates flare lights, breaking Rex out of the trance. The savage Rex realizes he has been tricked, becomes enraged and tries to attack Screweyes. However, Louie steps in and desperately tells Rex that killing Screweyes will not be worth it; these impassioned pleas serve to return the dinosaurs to their kind and friendly natures. Just then, Captain Neweyes arrives in his spacecraft and congratulates Louie and Cecilia, who proceed to kiss in front of a whole crowd of people. Stubbs announces his resignation from Screweyes' employ. Neweyes, Louie, Cecilia and the dinosaurs board the aircraft, leaving Screweyes to be swarmed upon by the crows. When the crows take off, all that is left of Screweyes is his fake eye, in which one of the crows takes and flies off with.
The dinosaurs spend the rest of their days in the Museum of Natural History, allowing children to see live dinosaurs, fulfilling their wishes. Meanwhile, Louie and Cecilia reconcile with their respective parents, and the two become a couple.
Rex returns Buster to his family before returning to the Museum of National History, humming the movie's theme song to himself.
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