Willis O’Brien project that he was never able to get off the ground. He recycled elements of it for BEAST OF HOLLOW MOUNTAIN, and friend and effects successor Ray Harryhausen later reworked the story as VALLEY OF GWANGI. Unlike the completed 1969 version, where Gwangi was an allosaur and the head predator of a hidden valley full of prehistoric beasts in 1912 America, O'Brien's original concept for Gwangi was a lone Tyrannosaurus of whom cowboys stumble upon in the Grand Canyon in more contemporary times. Gwangi is eventually captured by the cowboys and put on display at a wild west show. However lions that were also on hand escape and attack the dinosaur, leading to his own freedom. Gwangi dispatches the lions and then terrorizes a small town until he is finally forced off a cliff by a truck. It should also be noted that it was an elephant, not lions, who did brief battle with Gwangi in the '69 film.

Entry written by Madison Carter and Rafael C. Gonzalez