Heidi Klum, Kim Kardashian and Mariah Carey have all turned out pretty amazing costumes — and they’re just a start. Relive the funniest, spookiest moments from Halloween’s past.
1. Michelle Obama First lady Michelle Obama channeled a cat for a day, handing out candy to local school children at the White House in 2009.
2. Brad Pitt as D.J. Lance Rock from the show "Yo Gabba Gabba," alongside a zombie Angelina Jolie, took Zahara aka "Batgirl," trick or treating in Los Angeles in 2009.
3. Tyra Banks dressed as a sultry Kim Kardashian during a holiday-themed episode in 2009.
4. During a 2009 episode of "The Ellen DeGeneres Show," the comedic host dressed as "O, The Oprah Magazine." DeGeneres then actually graced the magazine cover in November 2009.
5. Heidi Klum dressed as a scary crow with Jessica Alba as Dora the Explorer at Klum's 10th annual Halloween party in Los Angeles in 2009.
6. Blake Lively dressed as Cleopatra while Martha Stewart posed as Medusa during a 2008 taping of Martha's show.
7. Kelly Ripa channeled her inner hippie while taking her kids out in 2007.
8. Lauren Conrad donned some feathers while in full-on flapper garb at the 2008 Pur Jeans Halloween party in West Hollywood, California.
9. Twilight's Ashley Greene went as a peacock and Kellan Lutz as Robin for Halloween 2009
10. In 2009, rocker Gwen Stefani dressed as Jessie from "Toy Story" to take her little ones trick-or-treating.
11. Heidi Klum dressed as a sexy cat at her 8th annual Halloween party in 2007.
12. Dressed as a lusty Little Red Riding Hood, Kate Beckinsale hit the streets of Santa Monica in 2008 to trick-or-treat with husband Len Wiseman, dressed as a spooky pirate skeleton, and daughter Lily, who pulled out all the stops as Marie Antoinette.
13. Proving that they're a match made in midnight snack heaven, Mariah Carey and husband Nick Cannon hosted a 2008 Halloween bash at New York City's Marquee nightclub dressed as a classic couple — milk and cookies!
14.Katy Perry combined celebrations for the spooky holiday and her 24th birthday when she hosted a party in 2008 at L.A.'s Siren Studios. "I had a cake that was a cadaver and its guts were everywhere," said Perry, who dressed as Queen frontman Freddie Mercury. "And I arrived in a hearse!"
15. Roberto Cavalli fooled more than a few guests when he dressed as rival designer Karl Lagerfeld at his annual Halloween bash in 2007. While Eve's ensemble was a little more subtle, she definitely got devilish when she hit the stage to perform for the crowd.
16. Lance Bass and Kim Kardashian teamed up — though it's not quite clear how their costumes sync up — when they celebrated Halloween 2008 at L.A.'s Stone Rose bar.
17. Milo Langdon flexed his Spider-Man muscles while in search of candy on the streets of New York City in 2007 with mom Liv Tyler and dad Royston Langdon.
18. Scarlett Johansson looked a little worse for wear between the eyes — thanks to a faux bullet hole on her forehead-when she was spotted leaving a spooky N.Y.C. bash at Bungalow 8 in 2005.
19. In 2006, Halloween aficionados Christina Aguilera and husband Jordan Bratman hit the Ghoulin Rouge party in New York City, dressed as a corpse bride and her ghastly groom.
20. At her annual bash in 2008, Heidi Klum lived up to her reputation as the queen of Halloween with a Hindu goddess costume. Klum's husband Seal was Heidi's sinister sidekick.
21. On the streets of New York City in 2006, a masquerading Gwyneth Paltrow might have blended in with the crowd in her bunny mask if not for the recognizable face of her adorable daughter Apple, who opted to trick-or-treat as Alice in Wonderland.
22. Forget the sexy maid getup, Anne Hathaway was born to play the queen (of the Nile). The always-glamorous actress kept her costume classy at Heidi Klum's 2004 Halloween Party, held at New York City night spot Marquee.
23. Josh Hartnett played it cool as folk legend Bob Dylan while model Gemma Ward unleashed her inner golden goddess at the Imperia vodka Halloween party at New York City's Rose Bar in 2007.