October: John Mayer and Katy Perry celebrates Halloween together.
Beyonce slings her web as Spider-WoMan.
Darren Criss and his smirk proudly show off his as Robin costume on the set of a "Glee" episode this year.
Stevie Wonder, in a skelton-friendly black ensemble, and Bette Midler, wreathed in black lace and roses, posed together at Midler's New York Restoration Project's Hulaween in New York City, last October.
Fergie sports long blonde locks for Halloween 2012.
"Glee's" Lea Michele channels the swan queen for Halloween on October 30, 2011.
The ever colorful LMFAO shows off their muscles (and feathers) as wrestling heroes on October 30, 2011.
Zac Efron is ultra-serious as a retro cop with a big gun as he poses with duo Aly & AJ, both in racy costumes.
Before being a proud mommy, Jessica Simpson was a proud mummy on October 31, 2011.
Amber Rose becomes Slash for Miranda Kerr's Sexy Circus Halloween Party in New York City in 2011.
A scholarly looking Lance Bass warms up to Wonderwoman Kim Kardashian during her Halloween bash hosted by PAMA at Stone Rose in LA on Oct. 30, 2008.
Blogger Perez Hilton puts a masculine spin on Lady Gaga for Heidi Klum's 10th Annual Halloween Party on Oct. 31 2009.
Russell Simmons looks like he dressed up as an 80s version of himself next to the devilish looking model Selita Ebanks at Heidi Klum's 10th Annual Halloween Party Presented by MSN and SKYY Vodka in Hollywood on Oct. 31, 2009.
Kelly Osbourne yolked it up when she dressed as an egg with Luke Worrall as a bacon strip at Heidi Klum's 10th Annual Halloween party in Hollywood on Oct. 31 2009.
The Hanson brothers get dressed up to crowd around the larger than life golden medallion Heidi Klum at Heidi Klum's 4th Annual Haunted Halloween Bash in NYC on Oct. 31 2003.
Cher was queen of the Nile in this Cleopatra outfit when she attended Bob Mackie's Halloween Party in Century City, Calif. on Oct. 31, 1998.
A yummy Mariah Carey compliments hubby Nick Cannon, as they pose as an adorable milk-and-cookies duo at their Halloween eve bash on Oct. 30 2008 in New York
Rapper Ice T is a stone cold pimp with his wife Coco at the Roberto Cavalli Vodka and Giuseppe Cipriani Halloween Party in NYC on Oct. 31 2007.
Backstreet Boy Kevin Richardson and his wife Kristin Willits tried to be stealthy with these spooky ninja outfit at the Ian Schrager's Mondrian Hotel Throws a Halloween Party 70's Style party on Oct. 31, 2002.
Jada Pinkett Smith and soon to be superstar daughter Willow Smith get Halloween started at the AIDS Foundation's 15th annual Dream Halloween benefit in Santa Monica, Calif. on Oct. 25 2008.
A terrifying Zombie/"Carrie" version of P!nk gets down with fans at a free Halloween concert on Santa Monica Boulevard in West Hollywood on Oct. 31 2002.
Sting plays the court jester to The Police guitarist Andy Summers' Charlie Chaplin during their Madison Square Garden performance in NYC on Oct. 31, 2007.
Christina Milian shows that ladybugs aren't just cute, but sexy too in this mid-rift showing Halloween costume she wore at the Pur Jeans Halloween Bast at STK in L.A. on Oct. 21, 2008.
Rap knight Diddy enchants princess Mariah Carey, during her annual Halloween Party on Oct. 31 2004 in NYC.
Jake Shears of the Scissor Sisters gets devious as the troublemaker Dr. Frank-N-Furter of the cult classic "The Rocky Horror Picture Show" on Oct. 31 2004.
Seal takes a bite out of Heidi Klum'Ã?Â?Ã?Â?s apple at her 7th annual Halloween party in LA on Oct. 31 2006.
A goofy looking Pete Wentz goes retro with a new 'fro at the 7th Annual Heidi Klum Halloween Party, Sponsored by M&Ms Dark Chocolate in LA on Oct. 31, 2006.
Britney Spears showed off her cheesy '80s side with friends at Heidi Klum's Halloween party in Los Angeles in LA on Oct. 31, 2007
Mariah Carey enchants the guests of her Halloween party as a sea bound mermaid on Oct. 31 2003 in London, England.
Dave Navarro went the sexy route in his red and furry lingerie outfit when he attened his Halloween Lingerie and Costume Ball in Hollywood on Oct. 28, 2006.
Aaron Carter shows off his Michael Jackson dance skills with this costume at the Camp Ronald McDonald for Good Times 17th Annual Halloween Carnival at Universal Studios in Universal City, Calif. on Oct. 25, 2009.
Pearl Jam dressed as Devo at PJ's Halloween show. Philadelphia Spectrum, 10/31/2009.