Kardashian, 38, went to the event in a beaded latex Thierry Mugler dress, notes PEOPLE. She said it took eight months to make the dress, which was held together with a knot at her waist.
"This is the first time in 20 years Mr. Mugler has designed for the House of Mugler. So to come and design this gown for me is such an honor," Kardashian told Vogue. "This is about eight months in the making … He envisioned me this California girl stepping out of the ocean, wet, dripping."
Kardashian went with a "wet" look for her hair to keep the ocean theme going and added droplets on her nails. Kardashian also shared the famous photos of a dripping wet Sophia Loren in Boy on a Dolphin, suggesting that might have been the inspiration for the look.
West's look was all-black, save for a white shirt worn under his zippered jacket. This was the first time West joined Kardashian at the event since 2016.
Kardashian told Vogue she was wearing a corset under her dress, joking that it was making it a bit hard to breathe.
"Once we're all at the top of the carpet we can all take a deep breath," she said. "I don't know if I can in this corset. I honestly had to do practice. It's a proper corset by Mr Pearl. I never had one like this, it is insane."
Kardashian's mother, Kris Jenner, also attended, with a new platinum long bob, which she said was daughter Kylie Jenner's idea.
"It was last minute craziness," she said of the new 'do.
The theme for this year's Met Gala is "Camp: Notes on Fashion," to coincide with the exhibit of the same name at the Metropolitan Museum of Art in New York. The title is a reference to Susan Sontag's famous 1964 essay "Notes on 'Camp.'"
Kardashian's appearance at the event came just after speculation about her fourth child already being born began. A report on E! Network's Daily Pop led some fans to think her surrogate already gave birth, but her representative said that was not the case.
Kardashian did not comment on the speculation, but she shared a text in which West wrote that they already had four kids.
"This is your life. Married with four kids. Get people out of jail. Cover of Vogue," the tweet read. "Go to church every week with your family. Dreams come true."
Kardashian and West are already parents to North, 5, Saint, 3, and Chicago, 1.
Photo credit: Dimitrios Kambouris/Getty Images for The Met Museum/Vogue