It took John Carter 100 years to make it from the page to the screen, but Edgar Rice Burroughs' other hugely famous character, Tarzan, has been doing the movies for decades and decades. In 1984 Hollywood decided to take him seriously in a movie that philosophically presages all of the 'realistic' superhero films and comics we've dealt with in the intervening years. That movie had a mouthful of a title: Greystoke: The Legend of Tarzan, Lord of the Apes.
But things didn't turn out exactly as planned. Writer Robert Towne was so unhappy with how things turned out that he gave his credit to PH Vazak... his dog. Then the script got nominated for an Oscar, making Vazak the only dog yet honored with an Oscar nod.
The movie itself takes some major liberties with the source material. It's notable for Christopher Lambert and the incredible Rick Baker ape FX.