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Someone's ready to howl at the moon! The singer shows his fangs at his annual Halloween bash in West Hollywood on Friday.
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Sarah Silverman & Michael Sheen
The comedian and her actor boyfriend use the holiday to spread a social message about smoking. "WE ARE LIVING REMINDERS," Silverman wrote on Instagram.
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The stylist is a stylish evil queen while jewelry designer pal Jennifer Meyer (Tobey Maguire’s wife!) channels old-school Madonna in Zoe’s Instagram.
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Lance Bass & Michael Turchin
The boybander is all about past fashion fads as Throwback Thursday, while his fiancé will get you, my pretty, as the Wicked Witch of the West in Bass’s Instagram.
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The rapper poked fun at an Internet meme comparing her Marlon Wayans in White Chicks, dressing up as the character in question (an FBI agent undercover as a socialite). "Bye haterzzzz," she captioned her Instagram video.
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Gym, tan, save Gotham? DJ Pauly D leaves the Jersey Shore behind to perform as the Caped Crusader at The Bank Nightclub inside the Bellagio in Las Vegas.
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"Rumour Has It" that’s Adele under that lace veil. The British songstress goes undercover as a black widow at Jonathan Ross’s Halloween bash Friday.
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Also at Lambert's bash, the TV host does her best Margot Tenenbaum. She wrote in a Instagram post, "I hope I did you justice @gwynethPaltrow!!!"
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SHENAE & JOSH
Nothing more flattering than someone dressing up as a dead version of you – right, Kelly Osbourne? Grimes-Beech and her husband Beech got the Fashion Police star's approval, as she posted, "I must say @joshbeech has the best costume!!!"
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The supermodel bugs out and cozies up to her Godfather boyfriend Vito Schnabel at her annual Halloween party Friday in N.Y.C.
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ICE-T & COCO
Coco is ready for battle with her rapper husband beside her while at Klum's party.
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MATT & MICHELLE
Greek goddess meet … creepy doll? McGorry and Trachtenberg make quite the odd couple at Heidi Klum's bash.
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Is this Commissioner Gordon several years later? The Gotham star looks wise beyond his years at the bash thrown by Heidi Klum.
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KATE & RITA
Looks like Moss has her impersonation of fellow supermodel and friend Cara Delevingne down pat as she and Ora attend the "Death of a Geisha" party in London on Friday.
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Since every day is Halloween for the flamboyant singer, she kept it classic as a ghost while getting her spook on in Paris on Friday.
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Keifer and Shawna Thompson, huge fans of Orange Is the New Black, get frisky at The Big 98's 2nd Annual Battle for the Bones Halloween Music Festival on Friday in Nashville, Tennessee.
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ADAM & BEHATI
Levine and Prinsloo get their aerobics in as they skip to a Halloween party in Los Angeles on Friday.
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BUSY & MARC
We'll take any chance to cozy up to a lumberjack. And Philipps agrees as she and husband Silverstein arrive at Adam Levine's party Friday in Los Angeles.
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The Game of Thrones star makes history look good as she attends Jonathan Ross's Halloween party in London on Friday.
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NICK & Olivia
Jonas and girlfriend Culpo arrive in roaring style to the 1 OAK Nightclub in Las Vegas on Friday.
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TONY & BETTE
Elvis (and Bette!) are in the building! Danza and Midler arrive at the 2014 New York Restoration Project's Hulaween at the Waldorf Astoria Hotel in N.Y.C. on Friday.
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Perry, also at Hudson's, proves she's hot stuff in her Flamin' Hot Cheeto costume.
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Happily ever after? The stylist and her husband, Rodger Berman, dress up as the Evil Queen and the Huntsman while attending Hudson's Halloween party.
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Out for round two, the TV host pays homage to Saved By the Bell's Kelly Kapowski (right down to the teased bangs and the varsity jacket!) at Hudson's party. Though we don't remember the storyline about her romance with Captain Jack Sparrow …
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Will the real Slim Shady please stand up? The 20-year-old channels rapper Eminem at Hudson's bash.
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GUY & ROCCO RITCHIE
Like father, like son! The party-ready pair wears matching Breaking Bad costumes to the Oct. 30 UNICEF Halloween Ball in London.
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The model might be expecting baby No. 2, but that doesn't mean she can't boogie at a Beverly Hills Halloween bash on Oct. 25.
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MATTHEW & RENEE
The recently married Glee star throws a Halloween bash Oct. 24 at Hyde Sunset Kitchen + Cocktails in West Hollywood, where he paid homage to Pulp Fiction's Vincent Vega and Mia Wallace with his wife.
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Also at the Glee actor's Oct. 25 party: the Arrow star, who goes undercover as Princess Fiona from Shrek.
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We see you, Captain America – ahem, Gerard Butler – who makes a super appearance at the Oct. 24 Casamigos Tequila party in Beverly Hills.
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Anyone up for a game of catch? The actor takes it back to Napoleon Dynamite as Uncle Rico while partying at Morrison's Halloween bash in West Hollywood on Oct. 25.
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Don't look so blue! The Pretty Little Liars star ruffles some feathers at the Oct. 25 Hyde party as the Twitter bird. (Try describing her adorable costume in 140 characters!)
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LANCE & MICHAEL
Bass and his fiancé look American Horror Story: Freak Show-ready while partying at Fred amp Jason's 9th Annual Halloweenie party in L.A. on Oct. 25.
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A bloody good time is had by the actress while partying in Beverly Hills on Oct. 25.
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A decidedly arresting Overstreet shows the East Coast some love as a member of the NYPD while hitting up the Oct. 24 Casamigos Tequila Halloween party in Beverly Hills.
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CINDY & RANDE
Forget Sonny and Cher! Instead, the couple channels Cher and Gregg Allman at the Oct. 24 Casamigos Tequila party. (Gerber is a partner at the tequila company.)
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The TV host glams up her camouflage while attending the Casamigos Tequila party on Oct. 24 in L.A.
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The socialite proves Minnie Mouse can be sexy at the Oct. 24 Casamigos Tequila Beverly Hills bash.