Rex is a timid and overly anxious Tyrannosaurus Rex toy in the Toy Story series. Despite his fearsome appearance, Rex is gentle and kind-hearted, often worrying about being replaced by newer toys. He is known for his self-doubt and insecurity, especially about his ability to roar, which he believes makes him less of a dinosaur. Rex provides comic relief in the series and is a loyal friend to Woody, Buzz, and the other toys, often joining them on their adventures and misadventures.