Actually, this may be something rare. In early 1983, some time prior to ROTJ's release, a Nickelodeon series called "Standby, Lights, Camera, Action!", hosted by Leonard Nimoy, showed a featurette on the ROTJ creatures that has never surfaced anywhere else. It still referred to the film as "Revenge of the Jedi" (this show ran the featurette after the title had been changed, so Nimoy had to explain the concept of a working title).

Here is the featurette excerpt that was aired on the show: https://www.youtube.com/watch?v=lr8s-CDOSMI

That clip is obviously abridged, and I've long wondered if it came from something longer. The fact that Team -1 referred to the reel they have as "The Creatures from Revenge of the Jedi" leads me to believe that it is in fact the full source of the clip from "Standby, Lights, Camera, Action!"