Return of the Ewok, an unreleased mockumentary starring Harrison Ford, Mark Hamill, and Carrie Fisher

In 1982 during filming for Star Wars Episode VI – Return of the Jedi, Ewok actor Warwick Davis and first assistant director David Tomblin made this mockumentary, "Return of the Ewok," about how Davis landed the role of Wicket W. Warrick. The film also stars Harrison Ford, Mark Hamill, Carrie Fisher, David Prowse, Peter Mayhew, Anthony Daniels, and Frank Oz.

"The film is a curiosity, half-documentary about the making of Jedi, half-fairy tale about a little boy who becomes an Ewok," Tomblin said in a 1984 interview in Starlog magazine. "He thinks he's the only Ewok in the world, but eventually finds there are others."

Return of the Ewok has never been officially released in its entirety. From Wikipedia:

Filming took place during the production of Return of the Jedi, including at lunchtimes and on weekends. "At lunch times, I would rush around and try and shoot pieces for it," Tomblin said. George Lucas financed the film, though costs were limited to expenses such as film stock. "Everyone contributed their time and talent for absolutely nothing," Tomblin said.

(Happy birthday, Emmett!)