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Alessandra Ambrosio was among a host of stars that attended the Casamigos Tequila Halloween party in Los Angeles on Saturday night, wowing in her Queen of Hearts outfit.
Fellow partygoers Cindy Crawford and Randy Gerber coordinated their outfits to a rock-star theme; Randy was a dead-ringer for Axl Rose, whereas his supermodel wife Cindy donned a black wig, top hat and inflatable guitar to complete her look as rocker Slash.
Also at the party were Sacha Baron Cohen and wife Isla Fisher, who were unrecognisable in full mismatched costume and masks, and Kelly Brook, whose Marie Antoinette-inspired costume showed off her incredible figure.
A slew of stars also attended Kate Hudson's early Halloween party at the actress's Pacific Palisades home on Saturday night.
Kate's mum Goldie Hawn and her partner Kurt Russell coordinated their outfits with Kurt wearing full lederhosen and a fake white beard, and 67-year-old Goldie looking much younger than her years in a dirndl and blonde wig tied plaited in pigtails.
Also invited were Paris Hilton, wearing the same skimpy teddy-bear leotard and foam finger that Miley Cyrus wore for her infamous VMA's performance, and Chelsea Handler, dressed as a pregnant woman.
A host of other stars shared snaps of their costumes on Twitter and Instagram.
New parents Fergie and Josh Duhamel, who are known for their love of dressing up, donned matching Day of the Dead-inspired costumes for a spooky pic posted on Josh's Instagram account.
He captioned the picture, "Hasta la muerte," which means "Until death," perhaps a play on the married couple's marriage vows.
Jessica Lowndes posted a photo of herself as the Phantom of the Opera, and popstar Rita Ora looked like she was having a ball as she shared a picture of herself in an American Indian headdress, as she got ready for a Halloween party in New York.
Nicole Richie posed with a much taller male friend in hilarious matching costumes inspired by the film Twins, and Rio Ferdinand looked a fright as a monster as he posed with fellow footballer Robin van Persie, dressed as Dracula.
Rosie Huntington-Whiteley shared a snap of her edgy outfit on Instagram, as she posed up a storm in a studded leather basque, bright green wig and sunglasses.
The model captioned the picture, "Happy Halloween," adding the hashtag, "#badgalroro," a play on Rihanna's Instagram name, "baggalriri."