Rex is a giant Tyrannosaurus and the leader of his dinosaur gang, (comprised by Woog the Triceratop, Elsa the Pteranodon and Dweeb the Parasaurolophus). The main protagonist of the animated movie We're Back! A Dinosaur's Story, Rex was formely a savage beast, before he would gain intellegence and benevolent side by Captain Neweyes, after consuming a "Brain Grain". He once started his adventure, along with his newfound friends, in New York City on the 20th century era. There, he made an easy bond with the children Louie and Cecilia. Despite his overall change, Rex has to find his own courage to overpower the forces of evil, including the notorious ringmaster Professor Screweyes.
Disney Vs Non-Disney Villains War
Rex's evil personality is used for the evil dinosaur, Sharptooth, rejuvated by Screweyes' magic. Though he appears under the influence of the evil ringmaster, Sharptooth turns against him, when Emperor Zurg uses the Uni-Mind to control the beast. After Screweyes' annihilation, Sharptooth regains consciouness and sets off to his own agenta. This is the last depiction of Rex's footage, shown in this war.
Non-Disney Villains Tournament
An evil dinosaur, who bears a strike resemblance to Rex, is used by various villains across the globe. The first time it is used by the Boogeyman, who summons a figment of the evil dinosaur to scare off Jack Spicer. Another depiction of the evil dinosaur briefly appears, summoned by the Kralahome, to deal with Valmont, though it is taken down by Valmont's magic.