Rancor and Luke Skywalker, POTF2, 1998
In 1997-1998, Kenner released a series of creature assortments. The Rancor Beast was included in this assortment.
Early prototypes were developed during the recreation process. The first prototypes were made of injection molded plastic from the original steel molds. Some evidence suggests that some of these first shots were modified by the Kenner model shop to potentially include new features.
Ultimately this amazing beast featured a new sculpt and a rubberized body for final production.
1998 Toy Fair Catalog
Another interesting note is that early samples of the Luke Skywalker figure included a much different color scheme than the production version.
Paint Sample / Engineering Pilot