The King Kong character was conceived and created by American filmmaker Merian C. Cooper. In the original film, the character's name is Kong, a name given to him by the inhabitants of "Skull Island" in the Indian Ocean, where Kong lives along with other oversized animals such as a plesiosaur, pterosaurs and various dinosaurs. An American film crew, led by Carl Denham, captures Kong and takes him to New York City to be exhibited as the "Eighth Wonder of the World".

Kong escapes and climbs the Empire State Building, only to fall from the skyscraper after being attacked by airplanes with guns. Denham comments "It was beauty killed the beast.", for he climbs the building in the first place only in an attempt to protect Ann Darrow, an actress originally offered up to Kong on Skull Island as a sacrifice (in the 1976 remake, her character is named "Dwan").

A documentary about Skull Island that appears on the DVD for the 2005 remake (originally seen on the Sci-Fi Channel at the time of its theatrical release) gives Kong's scientific name as "Megaprimatus kong" ("Megaprimatus", deriving from the prefix "mega-" and the Latin words "primate" and "primatus", means "big primate" or "big supreme being") and states that his species may be related to Gigantopithecus, though that genus of giant ape is more closely related to orangutans than to gorillas.

Merian C. Cooper became fascinated by gorillas at the age of 6. In 1899, he was given a book from his uncle called Explorations and Adventures in Equatorial Africa. The book (written in 1861), chronicled the adventures of Paul Du Chaillu in Africa and his various encounters with the natives and wildlife there. Cooper became fascinated with the stories involving the gorillas, in particular, Du Chaillu's depiction of a particular gorilla known for its "extraordinary size", that the natives described as "invincible" and the "King of the African Forest". When Du Chaillu and some natives encountered a gorilla later in the book he described it as a "hellish dream creature" that was "half man, half beast". These stories planted the seed of adventure in young Merian's mind.

Decades later in his adult years, 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.

Once the film got green-lit and it came time to design King Kong, Cooper wanted him to be a nightmarish gorilla monster. As he described him in a 1930 memo, "His hands and feet have the size and strength of steam shovels; his girth is that of a steam boiler. This is a monster with the strength of a hundred men. But more terrifying is the head—a nightmare head with bloodshot eyes and jagged teeth set under a thick mat of hair, a face half-beast half-human". Willis O'Brien created an oil painting depicting the giant gorilla menacing a jungle heroine and hunter for Cooper. However, when it came time for O'Brien and Marcel Delgado to sculpt the animation model, Cooper decided to backpedal on the half-human look for the creature and became adamant that Kong be a gorilla. O'Brien on the other hand, wanted him to be almost human-like to gain audience empathy, and told Delgado to "make that ape almost human". Cooper laughed at the end result saying that it looked like a cross between a monkey and a man with very long hair. For the second model, O'Brien again asked Delgado to add human features but to tone it down somewhat. The end result (which was rejected) was described as looking like a missing link. Disappointed, Cooper stated, "I want Kong to be the fiercest, most brutal, monstrous damned thing that has ever been seen!" On December 22, 1931, Cooper got the dimensions of a bull gorilla from the American Museum of Natural History telling O'Brien, "Now that's what I want!" When the final model was created (one that Cooper ultimately approved of), it had the basic overall look of a gorilla but managed to retain some humanesque qualities, such as a streamlined body and a removed paunch and rump, distinctive aspects of the gorilla's anatomy that Delgado purposefully removed. O'Brien would incorporate some characteristics and nuances of an earlier creature he had created in 1915 for the silent short The Dinosaur and the Missing Link into the general look and personality of Kong, even going as far as to refer to the creature as "Kong's ancestor". When it came time to film, Cooper agreed that Kong should walk upright at times (mostly in the New York sequences) in order to appear more intimidating.

Origin of the name

Merian C. Cooper was very fond of strong, hard-sounding words that started with the letter "K". Some of his favorite words were "Komodo", "Kodiak" and "Kodak". When Cooper was envisioning his giant terror gorilla idea, he wanted to capture a real gorilla from the Congo and have it fight a real Komodo dragon on Komodo island. (This scenario would eventually evolve into Kong's battle with the tyrannosaur on Skull Island when the film was produced a few years later at RKO.) Cooper's friend Douglas Burden's trip to the island of Komodo and his encounter with the Komodo dragons was a big influence on the Kong story. Cooper was fascinated by Burden's adventures as chronicled in his book Dragon Lizards of Komodo where he referred to the animal as the "King of Komodo". It was this phrase along with "Komodo" and "Kongo" (and his overall love for hard sounding "K"-words) that gave him the idea to name the giant ape "Kong". He loved the name, as it had a "mystery sound" to it.

When Cooper got to RKO and wrote the first draft of the story, it was simply referred to as "The Beast". RKO executives were unimpressed with the bland title. David O. Selznick suggested Jungle Beast as the film's new title, but Cooper was unimpressed and wanted to name the film after the main character. He stated he liked the "mystery word" aspect of Kong's name and that the film should carry "the name of the leading mysterious, romantic, savage creature of the story" such as with Dracula and Frankenstein. RKO sent a memo to Cooper suggesting the titles Kong: King of Beasts, Kong: The Jungle King, and Kong: The Jungle Beast, which combined his and Selznick's proposed titles. As time went on, Cooper would eventually name the story simply Kong while Ruth Rose was writing the final version of the screenplay. Because David O. Selznick thought that audiences would think that the film, with the one word title of Kong, would be mistaken as a docudrama like Grass and Chang, which were one-word titled films that Cooper had earlier produced, he added the "King" to Kong's name to differentiate.