Los Angeles, California – Kim Kardashian is saying "boo" and going blue!

If there were any doubts Kimmy Cakes would slay Halloween, they've all been put to rest.

The reality star and business mogul showed off her Halloween costume as X-Men's famous shapeshifter Mystique – and she was certainly showing off a lot of shape.

The skintight blue latex costume accentuated the star's famous curves, which she complimented with blue body paint, slicked back red locks, and yellow contact lenses. The Marvel mutant has been portrayed onscreen in the X-Men films by Rebecca Romijn and Jennifer Lawrence.

Britney Spears Britney Spears "thrilled" to reunite with son Jayden after years apart!

Kim sported the lewk for Saturday night of HalloWeekend, but it seems she may not have attended a themed shindig at all.

"That time I showed up to a birthday dinner in full costume when it wasn't a costume party," she wrote on her IG story." She accompanied the post posing for a photo with birthday girl Tracee Ellis Ross.

It looks like Diddy was also at the festivities, as the two took a selfie together and were seen in another photo among a partying crowd. The rapper was dressed as legendary DC character the Joker.

"Never broke character," the 42-year-old captioned the shot of the pair's supervillian transformations.

Of course, Kim's Halloween celebrations didn't stop there.

It looks like the Kardashian clan continued the fun with a Halloween party at Kim's house on Sunday.

The star posted videos of her decked out home complete with a graveyard, skeletons, and live "mummies."

Sister Kourtney Kardashian and her hubby Travis Barker showed up as the creepy pair of dolls from Bride of Chucky, while her daughter North came up with her own alien creation.

Sabrina Carpenter Sabrina Carpenter concertgoers get urinated on at her sold-out show!

"This is actually so creepy North! This is so crazy," Mama Bear Kim exclaimed as she checked out the costume. "North came up with these prosthetic designs," she added.

The party is just part of the Kardashians' super dose of Halloween spirit over the last week, with Kim giving a tour of her elaborate spooky house decor on IG and taking her kids on a haunted outing to Night of the Jack last week.

In true blue fashion, Kim looks like she's won Halloween.