As an adult, Cooper became involved in the motion picture industry. While filming The Four Feathers in Africa, he came into contact with a family of baboons. This gave him the idea to make a picture about primates. A year later when he got to RKO, Cooper wanted to film a "terror gorilla picture". As the story was being fleshed out, Cooper decided to make his gorilla giant sized. Cooper stated that the idea of Kong fighting warplanes on top of a building came from him seeing a plane flying over the New York Insurance Building, then the tallest building in the world. He came up with the ending before the rest of the story as he stated, "Without any conscious effort of thought I immediately saw in my mind's eye a giant gorilla on top of the building". Cooper also was influenced by Douglas Burden's accounts of the Komodo dragon, and wanted to pit his terror gorilla against dinosaur-sized versions of these reptiles, stating to Burden, "I also had firmly in mind to giantize both the gorilla and your dragons to make them really huge. However I always believed in personalizing and focusing attention on one main character and from the very beginning I intended to make it the gigantic gorilla, no matter what else I surrounded him with". Around this time, Cooper began to refer to his project as a "giant terror gorilla picture" featuring "a gigantic semi-humanoid gorilla pitted against modern civilization".