King Kong was the first film in box office history to be re-released. The original 1933 movie proved so popular that RKO decided to maximize on its success and release it again five years later, adding to its box office gross takings, and amazing audiences a second time around with its groundbreaking special effects.

When it first arrived in cinemas in 1933, King Kong ran for a total of 100 minutes. When it arrived for the second time in 1938, however, it was several minutes shorter. And for that matter, in the many decades since then, several different versions of the original film have made their way to cinemas—all with different runtimes. So, what happened?

One of the reasons for the different lengths comes down to lost scenes. One of the original prints of the movie included a gruesome set piece in which several crew members exploring Kong’s home, Skull Island, are knocked into a canyon by the beast and devoured by a series of horrifically oversized insects and spiders. Reportedly, the scene proved far too horrifying for 1930s audiences and was cut from the movie before its premiere in 1933.

But another reason the movie was considerably shorter in 1938 was all to do with censorship.

The original 1933 version also included an infamous scene in which Kong, having kidnapped the blonde bombshell Ann Darrow (played by Fay Wray), slowly begins removing and smelling her clothes.

In 1934, however, stricter decency rules came into play in Hollywood thanks to the introduction of the Production Code, so by the time King Kong returned to the cinema in 1938, this oddly salacious scene—along with another in which Kong pulls a different blonde woman from her bed and throws her to her death while scaling the Empire State Building—was removed from the theatrical cut.

Also left on the cutting room floor was a scene in which Kong stamps on several Skull Island natives; a scene in which a giant brontosaurus attacks several sailors in the waters around the island; and a scene in which Kong eats a newspaper reporter while on his doomed rampage through New York.

Sadly, most of these cut scenes have now been lost, and only sketches and still photos of them remain today. Some have been restored to the final print of the movie of the years, however—while Lord of the Rings director Peter Jackson famously added in the gruesome insect attack scene back into his 2005 remake.