In “Toy Story,” the timid green dinosaur is Rex.
Rex is a large, green plastic Tyrannosaurus rex toy in Andy’s collection. Despite his fearsome species, he is anxious, sensitive, and worried that he is not frightening enough. His nervous personality creates a comic contrast with his huge teeth and dinosaur design.
In the first film, Rex worries that Andy might replace him with a more intimidating dinosaur. Buzz Lightyear encourages him to improve his roar, helping Rex gain confidence during the toys’ efforts to find Woody and Buzz. Later films continue to portray him as loyal but easily frightened.
Rex is voiced by Wallace Shawn in the Toy Story films. “Dino” and “Raptor” are generic dinosaur descriptions rather than his name, while Trixie is a different triceratops toy introduced in Toy Story 3. Rex’s species is Tyrannosaurus rex, but his character name is simply Rex.