- AnnaLynne McCord channeled the Victorian era to host a Halloween party in Las Vegas
- Michelle Trachtenberg brought Tim Burton's "Blue Girl With Wine" artwork to life
- Christina Aguilera played a pirate at Maroon 5's Hollywood bash
(<a href="http://instyle.com" target="_blank">InStyle</a>)Need some Halloween costume inspiration? See how your favorite celebrities celebrate the most frightful night of the year:
Kim Kardashian"Poisonous!!!" the reality star Tweeted of her Poison Ivy outfit.
With jewelry by Graziela and Dana Rebecca Designs, Keibler looked boo-tiful as the host of a Halloween masquerade at the Hyde Bellagio in Las Vegas.
Christina Aguilera toted boyfriend Matthew Rutler as the knight to her queen for their festivities in Los Angeles.
Alyson HanniganThe actress played the role of a scarecrow, while daughter Satyana dressed as a pumpkin.
AnnaLynne McCordThe actress channeled the Victorian era to host the Haunted Seduction Halloween party held at Pure Nightclub in Las Vegas.
Michelle Trachtenberg The actress brought Tim Burton's "Blue Girl With Wine" piece of artwork to life in New York.
FergieWith teddy bear, trophy, sash, and tiara in hand, the singer played the perfect toddler beauty queen at Heidi Klum's Halloween bash at PH-D at Dream Downtown in New York.
Dita Von TeeseThe burlesque star pulled a piece out of her closet for Maroon 5's Hollywood Halloween. "Last minute decision to go out for Halloween...Scraping through my wardrobe for something that resembles a costume. No problem!" she Tweeted of her emergency costume.
Leona LewisThe singer represented a tragic pageant queen, sash and all.
Lauren ConradThe reality-star-turned-fashion-designer reworked a cute red and white polka dot dress into a Minnie Mouse costume.
Miranda KerrThe Victoria's Secret Angel stepped into the ring at Catch Rooftop in New York City to host a bash as a circus ringmaster.
See 51 more celebrities in Halloween costumes!