Halloween (Oct. 31) is the Met Gala for pop culture enthusiasts who love spooky season, and this year, the celebs did not disappoint.

Some took a laidback approach, like Justin Bieber's punk rock costume.

Meanwhile, others went more specific, like JB's wife Hailey Bieber, who recreated an iconic 1990s YSL runway moment with her floral costume.

"Happy Halloweekend 👻 inspo: YSL haute couture 1999," Bieber wrote on Instagram.

Meanwhile, some celebs took dressing up to the next level with makeup and costumes that wowed the internet, like Lizzo going fully-yellow as Marge Simpson, and Kim Kardashian turning blue as Mystique.

Billie Eilish's seemingly tongue-in-cheek costume also raised some eyebrows online when fans realized she seemed to be poking fun at the backlash surrounding her dating The Neighbourhood's Jesse Rutherford, who is 11 years older than her.

Eilish was dressed as a baby, complete with a bib and diaper, while Rutherford went as an old, gray-haired man.

Many called the duo's costume "disturbing" and "weird."

TikToker and influencer Addison Rae took a stab at Lady Gaga's famous 2009 VMAs performance of "Paparazzi," where she wore all-white while fake blood gushed all over her.

"I’ll follow you until you love me," Rae captioned her Instagram post, referencing the song's lyrics.

Singer and actor Halle Bailey also went all out with her Avatar-inspired costume, writing on Twitter, "Always wanted to be an avatar."

Riverdale's Lili Reinhart, Madelaine Petsch, and Camila Mendes also went scarily accurate with their take on the Sanderson sisters from the spooky classic Hocus Pocus.

The costume was another play on the trio's contrasting hair colors as their aptly-named TikTok account, @blondebrunetteredhead, reflects.

And in a hilarious move that trolled his older brother Joe Jonas, the Jonas Brothers' little brother Frankie Jonas and his girlfriend went as Joe and his ex Taylor Swift in the JoBros' 2009 concert film Jonas Brothers: The 3D Concert Experience.

See more celebrity Halloween costumes, below:

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