In 1973, Peter Brown, who had been a member of the board of directors of Apple Records and General Manager of Beatles & Co, acquired the European film rights to the John Carter character. In an effort to entice potential investors, and to generate interest from studios, he hired the French playwright and short story author Roland Arrabal to create a script treatment and synopsis. Brown became a fan of Arrabal's after seeing a production of his play "Sept Péchés" at a small, 25 seat theater in basement of the Baron's Pub in Croydon.
Arrabal, known for his eccentric, iconoclastic style, went straight to work creating a treatment that bore only a passing resemblance to Edgar Rice Burroughs's character. Using the ideas of reincarnation and colonialism as his jumping-off point, Arrabal concocted a Mars of peaceful, large-breasted and wide-hipped feminine entities who are corrupted by the former Confederate soldier's influence. Arrabal's script would have featured copious amounts of blood and gore, and wild sex between Carter and the Princess, who was to have been at least twice, and perhaps three times, as big as him.
Also, here's one of the pieces of concept art:
And here is the first page of the script notes, as written by playwright Roland Arrabal:
You can read the rest of the piece here.