Reaction to Valerian and the City of a Thousand Planets may have been mixed, but one thing was unanimous: Rihanna playing a shape-shifting alien named Bubbles was a highlight. In this behind-the-scenes featurette, debuting on ET, RiRi reveals which of her many looks -- disco queen, French maid, Cleopatra and more -- was the hottest. Not like sexy, but actually hot.

"I loved the nurse outfit. That one was a tricky little number, because it was all latex," Rihanna says. "Literally, I had to take breaks to, like, towel down the sweat out of my costume. It was crazy. But I did lose some weight for the next scene, which was tribal and my stomach was all out!"

Valerian was a passion project for visionary director Luc Besson, one he spent many, many years attempting to bring to the screen, and he told ET that he cast Rihanna once she proved to him that she is "serious about acting." The home video for the sci-fi epic release includes plenty more bonus material about the making of the movie, including interviews with Valerian himself, Dane DeHaan, and Cara Delevingne.

Here is the official breakdown of the movie's special features:

"The Valerian and the City of a Thousand Planets home entertainment release features the five part documentary “Citizens of Imagination: Creating the Universe of Valerian” which delves into the creation of the characters in the film, including both humans and alien lifeforms, along with insight into the production design, special effects, and stunts. The home entertainment release also features a “The Art of Valerian” photo gallery, and Enhancement Pods. The 4K Ultra HD and Blu-ray versions feature Dolby Atmos® audio remixed specifically for the home-theater environment, to place and move audio anywhere in the room, including overhead. The 4K Ultra HD Blu-ray also features Dolby Vision™ high dynamic range (HDR), growing Lionsgate’s library of titles featuring both Dolby Vision and Dolby Atmos. Dolby Vision transforms the TV experience in the home by delivering greater brightness and contrast, as well as a fuller palette of rich colors. Together with the captivating sound of Dolby Atmos, consumers will experience both cutting-edge imaging and state-of-the-art sound technology for a fully immersive entertainment experience."

Valerian and the City of a Thousand Planets is available digitally now and on 4K Ultra, Blu-ray and DVD on Nov. 21.

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