Halloween 2019

Lisa Rinna Is J. Lo

BEVERLY HILLS, CALIFORNIA - OCTOBER 25: Lisa Rinna attends the 2019 Casamigos Halloween Party on October 25, 2019 at a private residence in Beverly Hills, California. (Photo by Michael Kovac/Getty Images for Casamigos)

I mean, obviously this is great. An evergreen costume now made timely anew by the fact that La Lopez herself famously re-wore it.

Jessica Biel and Timberlake

BEVERLY HILLS, CALIFORNIA - OCTOBER 25: Jessica Biel and Justin Timberlake attend the 2019 Casamigos Halloween Party on October 25, 2019 at a private residence in Beverly Hills, California. (Photo by Michael Kovac/Getty Images for Casamigos)

I think Jessica Biel might secretly be kind of funny -- I know, I know, we're all mad at her for popping up and announcing she's a semi-anti-vaxxer, which was...bonkers of her. But coming in costume as Justin is funny. (That's him with her, as a microphone.) If you two REALLY want people to fall back in love with you, though, show up as Britney and Justin in the matching denim looks.

Angelica Ross as a Clover from Bring It On (PRESUMABLY Gabrielle Union)

Mandatory Credit: Photo by Shutterstock (10456658a) Angelica Ross 'American Horror Story' 100th Episode Celebration, Arrivals, Hollywood Forever Cemetery, Los Angeles, USA - 26 Oct 2019

I believe this costume has, in fact, brought it -- although it's hard to compete with actual Gabrielle Union in this same costume.

Lottie Moss

Speaking of Britney, this is her in the Toxic video, right?

Nicola Hughes, also as Britney

Mandatory Credit: Photo by Mark R Milan/Shutterstock (10456781p) Nicola Hughes M Restaurant Victoria Halloween party, London, UK - 26 Oct 2019

Not interested in Toxic Britney? How about Oops Britney? (Britney has created a LOT of iconic looks appropriate for Halloween costumes, actually.)

Laverne Cox

I do not know what this is, and also Laverne doesn't seem to know totally either? (If I'm reading her right.) God bless Laverne Cox for being like, "I totally threw this together." She looks totally cute, though.

Cardi B

Naughty/Evil nurse -- a classic.

Rande and Cindy

BEVERLY HILLS, CALIFORNIA - OCTOBER 25: Rande Gerber and Cindy Crawford attend the 2019 Casamigos Halloween Party on October 25, 2019 at a private residence in Beverly Hills, California. (Photo by Kevin Mazur/Getty Images for Casamigos)

From what I can tell, the Casamigos party -- THE big Hollywood Halloween party on the west coast -- was generically hippie themed, and I swear that's the theme EVERY year. I feel like Cindy just wants a party where not wearing heels is VERY in costume.

Molly Sims as I Dream of Jeannie

Mandatory Credit: Photo by ROGUT/starmaxinc.com/Shutterstock (10457093j) Molly Sims Casamigos Halloween party, Los Angeles, USA - 25 Oct 2019

Molly Sims always commits, and this is a very cute, well-done costume on her.

Maria Menounos and Keven Undergaro

Where do you even get the idea to be Old School McDonalds Employees?

Emma Roberts

'American Horror Story' had a big party for it's 100th episode and people were confused as to whether it was an actual costume party or not. Some people came in full costume. Some people wore normal clothes but, like, wacky contact lenses or black lipsticks. Some people wore stuff like this, where you're like...IS this a costume? (We got a credit that it's by Vivetta, and it's "the same as the runway" so...no??)

Kathy Bates

But Kathy COMMITTED!

Evan Peters and Halsey

Mandatory Credit: Photo by NINA PROMMER/EPA-EFE/Shutterstock (10457431g) Evan Peters (L) and US singer Halsey (R) arrive for FX's American Horror Story 100th Episode Celebration at Hollywood Forever Cemetery in Hollywood, Los Angeles, California, USA, 26 October 2019. American Horror Story: 1984, the ninth installment of the award-winning anthology series, currently airs on FX in the US. FX's American Horror Story 100th Episode Celebration in Hollywood, Los Angeles, USA - 26 Oct 2019

These two also mostly committed -- they're Sonny and Cher. (I feel this requires more commitment from Evan than it does Halsey, who looks very cute in this dress.)

Shanina Shaik

Like, this is the UNICEF Masquerade Ball. Is this a costume......? Or just a mildly wacky dress? I feel like she's hedging her bets here. (No judgement, I'd probably also hedge mine at this event.)

Avril Lavigne

Avril, on the other hand, went full costume. As....????????? I don't know! Maybe she didn't. Maybe she dresses like this now!

Tallulah Belle Willis

And Tallulah Belle Willis wore a VERY cool tux and stuck an eye on her head. This is actually a very chic costume AND when she takes off the eye, she just looks cool in general.

Olivia Culpo

Is she...just a salute to the noble ruffle??

Billie Eilish

I do NOT know what Billie is. But she does look sort of scary, so...good?

Nina Dobrev and Arielle Vandenberg

Meanwhile, Nina has gone AS Billie. She nailed it -- and also this looks comfy. Arielle is "wedding Beiber," which she ALSO nailed. Way to go, ladies.

Jack Brooksbank

"WHAT is Mr. Princess Eugenie doing at this PARTY?!?!?!" I squawked before I remembered that Mr. Princess Eugenie WORKS FOR CASAMIGOS. (I don't believe she was there; I didn't see pics if she was. She may have been been lurking in the shadows.)