Many filmmakers have made cameo appearances in their own movies, the most famous being Alfred Hitchcock. Similarly, director Peter Jackson also has a long history of including himself in his films, and his adaptations of The Lord of the Rings and The Hobbit are no exception. Each of his six movies set in J.R.R. Tolkien's Middle-earth features one brief appearance from the fun-loving New Zealand director. Some of these cameos last for only a split-second, but a couple of his characters actually contribute to the plot, even if only in a small way.
Source：https://www.cbr.com/peter-jackson-cameos-lord-of-rings-hobbit/
