Since the beginning of movies, there have been the films that never got completely made. Some were stopped in mid-production, others never got off the script page. A great number of films pertaining to the genre of giant monsters has fallen into this dark crevice of "unmade movies". Here, we hope to list (never a complete list, but as much as possible) all the various Giant Monster movies that were announced or seriously considered before falling by the wayside. All in all, it's a lighter look at "what might have been."
For brevity's sake, we are attempting to avoid movies/scripts/concepts that did end up getting made with very little alteration. For example, we will list the version of THE MYSTERIANS that intended to include a monster ultimately very different from the one that was used. However, we will refrain from listing every version of JURASSIC PARK that included different plot points that were later changed. Also, we will include films that were planned by one source, but finally made by another. For instance, we will list Willis O'Brien's GWANGI, even though Ray Harryhausen eventually adapted it as VALLEY OF GWANGI.