T-Rex’s First Major Role

During the filming of Jurassic Park (1993), T-Rex was known to sweat profusely as it was his first major role in 55 million years

A behind-the-scenes photo shows a person working on a large T-Rex costume or animatronic on the set of Jurassic Park. The joke treats the dinosaur as an inexperienced actor nervously sweating before his first major role in millions of years. It is used as a reaction to feeling anxious or overwhelmed in a new situation.