In 1972 Ballantine Books hired Alan Dean Foster to write a novelization of the film, which had just been acquired for US distribution. However, at the time the only available copy of the script was in Italian, which Foster couldn't read, so the publisher arranged for him to view the film; but the print that was screened was also only in Italian, with no English subtitles. So Foster wrote a new novel from scratch, finding inspiration in the Frank Frazetta painting that the distributor had chosen for the US poster.