The AMA host wore a gold mask paired with matching metal fingernails, a black veil and a floor-length strapless gown on the red carpet.
PHOTOS: 2021 AMA red carpet
This year's AMA red carpet was all about the sparkle and shine: most-nominated artist Olivia Rodrigo sported a glossy baby blue gown.
Slits and cutouts also had a moment this year: Performer Chloe's gown featured a hip-high slit beneath a waist-hugging cutout and Halle Bailey donned a midriff-revealing velvet brown dress.
Cardi won't let fans spread "rumors" about her look ahead of the fan-vote awards show.
"Can you give some scoop of who [you're] wearing on the amas?" one fan tweeted at the rap superstar.
"You gone have [to] tune in" she responded.
The "Bodak Yellow" and "I Like It" artist wore a sleek black halter gown for the ceremonial red carpet rollout Friday.
"I'm excited to wear all the clothes that I have... 'cause I'm giving fashion," she said during the event.
South Korean superstars BTS were crowned artist of the year at the American Music Awards on Sunday, brushing aside challenges from Taylor Swift, Drake and The Weeknd as they took home a total of three awards. Olivia Rodrigo came into the night with a leading seven nominations but only took home the crown for favorite new artist of the year.
Performers included Coldplay and BTS, Carrie Underwood and Jason Aldean, Jennifer Lopez, Bruno Mars and Anderson .Paak. joining forces as Silk Sonic, Bad Bunny, Diplo, Mickey Guyton and Tyler, The Creator.
Stream the 2021 American Music Awards the next day on Hulu.
The Associated Press contributed to this report.