Colbert, who has said he's a huge J.R.R. Tolkien and Lord of the Rings fan and can read elvish, told Playboy he traveled to New Zealand to observe some of the filming of the Hobbit trilogy.
"Peter Jackson invited me to the set last year," he said. "I flew out and watched them shoot some scenes and went to some locations. I saw a 25-minute cut, and it was amazing. Jackson knows I'm a big fan of the films."
When asked if he would appear as an extra in one of the films, Colbert smiled and replied, "could be."
There's no word on which of the three films Colbert will make his appearance, The Hollywood Reporter said, though the source, whose name was not reported, said it will not come in the first film.
The first film, "The Hobbit: An Unexpected Journey," hits theaters Dec. 14. The second film, "The Hobbit: The Desolation of Smaug," will be released Dec. 13, 2013, while the third movie, "The Hobbit: There and Back and Again," is scheduled to be released July 18, 2014.
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