The billionaire beauty mogul attended the Met Gala at New York's Metropolitan Museum with this year's theme being In America: A Lexicon Of Fashion – in celebration of US fashion.
Fans were stumped on how her outfit related to the dress code, but she later wrote on Instagram, "What's more American than a T-shirt head to toe?!"
After her arrival, fans took to social media en masse to mock the Keeping Up With The Kardashians alum, comparing her to a "dementor" from Harry Potter.
Kardashian also dressed in head-to-toe black for the afterparty, this time with a mask covering her eyes.
The questionable display feels like a massive plug for West's new album, Donda.
Kardashian earlier hinted at adopting this sort of look for today's event after checking into her New York hotel at the weekend wearing a similar all-black leather outfit.
The ensemble, which she wore as she arrived at the Ritz-Carlton, included stiletto heel boots, loose-fitting pants, trench coat and complete head covering with room for a ponytail to stick out the back.
The number is a far cry from Kardashian's usually glitzy and glamorous Met Gala outfits.
In 2019, the reality star looked as if she'd just stepped out of the ocean in a latex Thierry Mugler number splashed with beaded crystals, which took eight months to craft.
The costume gala, which is celebrating an all-American theme this year, was cancelled in 2020 because of the coronavirus pandemic.
The Met Gala is an annual fundraising event for the Metropolitan Museum of Art's Costume Institute, and is one of the leading sources of funding with contributions anticipated to have surpassed $270 million in total after the 2019 event.