Kate Beckinsale & Len Wiseman
The beautiful British duo make it a couple's costume night.
David Arquette
The Scream star is all shook up for a bash in Sin City.
Vinny Guadagnino & Ronnie Ortiz-Magro
The Jersey Shorers channel their castmates on the set of MTV's Seven. Hey, Vin, nice stems!
La Toya Jackson
Looking like a space-age Eartha Kitt, La Toya totally wigs out as a B-52s wannabe at Millions of Milkshakes in WeHo. Just don't ask us if she brought all the boys to the yard.
Snooki
In a pickle, but in a good way, the Jersey Shore star steps out dressed as her favorite food for the "Nighmare in Jersey" bash at Jet Nightclub in Vegas. Somebody get Snickers some bronzer, STAT!
Holly Madison
Throwing her annual Hollyween party at Studio 54 in Vegas, the reality star dolls herself up as Princess Aurora from Sleeping Beauty. Sweet!
Amanda Seyfried
Living the plush life at Kate Hudson's Halloween bash in Pacific Palisades, the gorgeous young star dresses up as her dog. We're sure she'd hear whistles either way.
Heidi Klum
From supermodel to superhero, Heidi suits up for her legendary Halloween bash (held at Lavo in New York).
Tina Fey & Will Ferrell
The wise-cracking duo kill two birds with one stone, promoting their animated movie Megamind in costume during the Today show's Halloween episode.
Meredith Vieira
Who could forget this outfit?! Mer rocks her best "Poker Face"—and we say this intergalactic costume is just as awesome the second time around.
Natalie Morales
Two words: Bieber. Fever.
Craig Ferguson
The Late Late Show host gets an early, early start on Halloween with a little monster mash.
Ellen DeGeneres
She's a dead ringer for Cousin Itt, but nope, the talk-show host explains: "In case you don't know, I'm Snooki's pouf. That's Snooki down there. I'm the pouf. She's the actual size. She is that short. I met her in person."
Julian McMahon
The former Nip/Tuck star struts his sexy stuff as sweet transvestite Dr. Frank-N-Furter at the Rocky Horror Picture Show tribute event in L.A. to benefit the Painted Turtle, a camp for children with life-threatening illnesses.
Evan Rachel Wood
The actress looks downright marvelous as Magenta upon arriving at the Rocky Horror Picture Show event.
Rachael Ray & John Cusimano
The cute cook and her equally adorable hubby are quite the animated pair as Jessica and Roger Rabbit.
Wendy Williams
The talk-show host loves Lucy as she transforms herself into TV icon Lucille Ball.
Kelly Osbourne, George Kotsiopoulos, Snooki, Joan Rivers & Giuliana Rancic
With help from the Jersey Shore guidette, the Fashion Police hosts get their Halloween on.
Holly Madison
Playfully sweet and sexy, the model strikes a pose as Tinkerbell at the Fright Dome Haunted House at Circus Circus Casino in Las Vegas.
Rihanna & Coco
Halloween 2009
Something tells us Tony the Tiger didn't have these two in mind when he declared, "They're grrrreat!" But Ice-T's mate (dressed appropriately as a porn star) and Ri-Ri look just that.
Katy Perry
The singer took the front hump of the camel—pal Shannon Woodward drove the rear—before giving up on the sweaty suit and promising via Twitter to be something a bit more "slutty" next year.
Kelly Killoren Bensimon
The Real Housewife of New York City channels a real German beer wench at Joonbug.com's 8th Annual Masquerade Ball.
Blake Lively
More pretzels, please! Something tells us the rest of the revelers at 1Oak would happily join the mile-high club with this Gossip Girl beauty.
Miley Cyrus
While some hand out Reese's Pieces on Halloween, Miley simply dispenses peace.