It’s east versus west, giant reptile versus mega-mammal, the “Big G” versus the “Eighth Wonder of the World.” Godzilla vs. Kong—a new slugfest from Legendary Pictures—is set to be released in theaters and on HBO Max on March 31, 2021. But it won't be the first time these two iconic movie monsters have faced off. They met once before in 1962’s King Kong vs. Godzilla—a crossover battle for the ages that also featured a rampaging octopus and a future Bond Girl. Not to mention the craziest tree-related violence you’ll ever see outside an M. Night Shyamalan flick.

1. Originally, King Kong was supposed to do battle with a Frankenstein monster.

Released by RKO in 1933, the first King Kong movie used stop-motion effects provided by the great Willis O’Brien. After some other projects fell through, O’Brien wrote a treatment for a new sequel he called King Kong vs. Frankenstein (alternate title: King Kong vs. the Ginko). In O’Brien’s original story, the great ape fights a monster who had been stitched together from various animal parts by a member of the Frankenstein family. Producer John Beck agreed to see if anyone was interested in buying the script. Ultimately, he sold it to Japan’s Toho Studios—without telling O’Brien. Toho decided to replace the Franken-beast with their own original character: Godzilla.

2. King Kong vs. Godzilla was the first movie to depict either King Kong or Godzilla in color.

Kong has been climbing skyscrapers and wooing blondes ever since the Great Depression, which gives him seniority over Godzilla, whose debut film didn’t come out until 1954. That Toho classic and its first sequel, Godzilla Raids Again (1955), were both shot in black and white. So was the original King Kong and its famously rushed RKO follow-up, Son of Kong (1933). Fans finally got to see both giants in glorious color when King Kong vs. Godzilla arrived in theaters.

3. Director Ishirô Honda satirized the TV industry in King Kong vs. Godzilla.

Ishirô Honda, the visionary director behind Godzilla (1954), Rodan (1956), and Mothra (1961), used King Kong vs. Godzilla to comment on popular culture. The plot gets going when the head of a Japanese pharmaceutical company decides that kidnapping Kong would be a great way to boost ratings for the TV show he sponsors. What could possibly go wrong? "People were making a big deal out of ratings," Honda said. "But my own view of TV shows was that they did not take the viewer seriously, that they took the audience for granted ... so I decided to show that through my movie."

4. Stop-motion animation was used sparingly in King Kong vs. Godzilla.

Special effects director Eiji Tsuburaya was a big fan of O’Brien’s stop motion work. So he found ways to include this technique in King Kong vs Godzilla, even though the film mostly relies on actors in monster costumes (i.e. “suitmation”). There’s a snippet of stop motion in the final battle, when Godzilla leans on his tail to kick Kong in the stomach. And earlier in the movie, a giant octopus snatches one of the hapless Faro Island residents. That effect was realized through some (very brief) stop motion artistry.

5. King Kong went through a few redesigns for King Kong Vs. Godzilla.

Steve Ryfle’s 1998 book, Japan’s Favorite Mon-Star: The Unauthorized Biography of “The Big G” describes an early concept model built by Tsuburaya’s team as a somewhat “cute and cuddly” ape who looked “fat with coarse hair and long legs and arms.” It was the first of many Kong designs the effects director rejected before settling on the right look.

6. King Kong Vs. Godzilla's human cast features future Bond Girl Mie Hama.

Nearly 30 years after King Kong chased Fay Wray around the Big Apple, King Kong vs. Godzilla introduced the gigantic gorilla to Fumiko Sakurai during his Tokyo rampage. Sakurai was played by Mie Hama, who would go on to play Kissy Suzuki in the 1967 James Bond thriller, You Only Live Twice. Late in King Kong vs. Godzilla, Kong snatches Sakurai and carries her to the top of the National Diet Building, where Japan’s legislature meets. Fun Fact: The Big G destroyed that same structure in the first Godzilla movie.

7. The big fight scene in King Kong vs. Godzilla was choreographed by the suit actors.

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Veteran actor Haruo Nakajima had been suiting up to play Godzilla since 1954. For the climax of King Kong vs. Godzilla, he brought something new to the table: pro wrestling moves. With co-star Shoichi Hirose (who portrayed Kong), Nakajima choreographed a frenetic monster battle heavily influenced by the sport. “I used the elements of pro wrestling, as well as the movements of the original Godzilla,” Nakajima said. “I modified the way he moved, so it was quite difficult. None of the staff, including Mr. Tsuburaya, knew anything about staging a fight."

8. Some of the music in the American version was written for 1954’s Creature From the Black Lagoon.

King Kong vs. Godzilla opened in theaters in Japan on August 11, 1962. American audiences wouldn’t get to see the movie until the following summer. Beck produced an English-language version which was released stateside by Universal-International on June 3, 1963. This revised cut scrapped almost all of the original score composer Akira Ifukube wrote for the film. Beck’s team replaced the majority of it with tracks borrowed from American movies, including Creature From the Black Lagoon.

9. There’s an old myth about the ending of King Kong vs. Godzilla.

Both the Japanese and English-language versions of the movie end with Godzilla and Kong tumbling off a cliff and falling into the Pacific Ocean together. Yet when the water settles, only Kong resurfaces—making him the official winner of the bout. Despite this, in 1963, the American magazine Spacemen claimed two very different endings had been shot. “If you see KING KONG vs. GODZILLA in Japan, Hong Kong, or some Oriental sector of the world, Godzilla wins!” declared Spacemen. “On the other hand, in the USA & England, for instance, Kong wins!” That’s not accurate—but the “two-endings” myth was later repeated by the Crestwood Monster House book series, Famous Monsters of Filmland magazine, and an edition of the Trivial Pursuit board game. Even sportscaster Bob Costas got it wrong.

10. One of the Pirates of the Caribbean Movies used the octopus from King Kong vs. Godzilla as an animation reference.

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Hal Hickel had his work cut out for him. As the computer animation director for Pirates of the Caribbean: Dead Man’s Chest (2006), it was his job to make the film’s giant kraken look as realistic as possible—both in and out of the water. According to Hickel, King Kong vs. Godzilla had “the best” reference footage he could find of an octopus crawling around on dry land. Remember the giant cephalopod who attacks Kong’s island during the movie? In most shots, it was portrayed by a real flesh-and-blood octopus that Tsuburaya plopped onto a miniature set.

11. Toho wanted to produce a rematch in the 1990s.

King Kong vs. Godzilla was a box office smash, inspiring Toho to make two more giant monster crossovers—Mothra vs. Godzilla and Ghidorah, the Three-Headed Monster—in 1964. A whopping 32 Japanese Godzilla films have been released altogether as of this writing. To help celebrate the studio’s 60th anniversary in 1992, Toho considered remaking King Kong vs. Godzilla, but the rights to Kong were prohibitively expensive.