"This is Rex! The meanest, most terrifying dinosaur who ever lived!" —Andy Davis shows Rex to Bonnie Anderson Rex is a supporting character in the Toy Story franchise. He is a plastic green Tyrannosaurus Rex, who served as the main character of Partysaurus Rex. Rex is insecure about his lack of ferociousness, as he's not scary enough and seems to just be annoying. Rex's worst fear (after Sid) is that Andy may gain another, scarier dinosaur to replace him. "But what if Andy gets another dinosaur,