The Star Wars film franchise boasts a whole host of hidden cameos, but not many people realize that Cheers star John Ratzenberger had a bit part in The Empire Strikes Back. John Ratzenberger is best known for his long-running role as know-it-all mailman Cliff Clavin on classic sitcom Cheers. Appearing in all but one of Cheers’ 270-plus episodes, Ratzenberger earned a couple of Emmy nominations for his troubles and appeared in character as Cliff on shows including Wings, St. Elsewhere and The Simpsons.

Beyond Cheers, Ratzenberger has become pretty famous as Pixar’s go-to voiceover guy. In fact, he’s voiced a character in every single Pixar feature film that’s ever been released. Pixar fans might recognize Ratzenberger as the voice behind recurring characters like piggy bank Hamm in the Toy Story movies and haulage truck Mack in the Cars franchise, but he’s also voiced characters like nervous head waiter Mustafa in Ratatouille and Scottish royal guard Gordon in Brave. He’ll continue the tradition in the future too with as yet unknown roles in forthcoming Pixar features Onward and Soul.

Related: Every Pixar Movie Role John Ratzenberger Has Played

Way before he became a Pixar favorite, and even a couple of years before he became a household name playing Cliff on Cheers, John Ratzenberger had a blink-and-you’ll miss it cameo in Star Wars: Episode V – The Empire Strikes Back. His character isn’t referred to by name, but he’s credited as Major Bren Derlin in the credits and is the Rebel Alliance officer who tells Princess Leia they must close the shield doors of the Echo Base after Luke and Han fail to return, leaving them at the mercy of the freezing weather on ice planet Hoth.

John Ratzenberger The Empire Strikes Back

Seven mainline Star Wars movies later and John Ratzenberger has yet to reprise his role as Major Bren Derlin, although he did voice the character in the non-canon animated series Lego Star Wars: The Freemaker Adventures. Who knows? Perhaps Major Bren Derlin could make his way into the next three Star Wars films but considering director Rian Johnson intends to craft an all-new trilogy it doesn’t seem too likely Ratzenberger will be joining the cast.

Interestingly, according to The Numbers, John Ratzenberger is the third-highest grossing actor in terms of how much money the movies he’s been in have made at the American box office. That’s thanks largely to his ongoing work with Pixar and their hugely popular films alongside his bit part as Major Bren Derlin in Star Wars.

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