Joyce Bonelli and Kim Kardashian
@kimkardashian: Karl, Grace, Anna, Andre
@kimkardashian: Karl, Grace, Anna, Andre
@kimkardashian: Look #1- Skeleton
@beyonce: Janet and MJ
The pop star (@justinbieber) as the Red Ranger, posing with little brother Jaxon.
@JCChasez: "Just found an amazing costume at http://Instagram.com/junk4joy #respect4 @robinwilliams#nanunanu#RestInPeaceRobin"
@adamlambert: "@coltonlhaynes whaaaaaaaaaat"
@lancebass: "#Halloweenie"
@ddlovato: "Tonight was so much fun… Impromptu Halloween end-of-tour costume party with everyone a part of #demiworldtour"
@hillaryscottla: "#fbf to Wednesday when I was a disco ball(sort of) holding a pig between two kegs…"
@Matt_Morrison: "Thanks to @FreixenetUSA for an amazing birthday/Halloween celebration. #FXHalloween"
Beyonce dressed as Janet Jackson a la "Rhythm Nation" while posing backstage with @babyjakeali
@kimkardashian: "My little stinker is waiting to show daddy her costume. Halloween has started early this morning"
@katyperry: "IDFWU *drops mic*"
@taylorswift: "Cause, darling I'm a nightmare dressed like a PEGACORN. #HappyHalloween!"
@rachelzoe: "Headed out as evil queen and the Huntsman with my @rbermanus #allhallowseve #meandmybabe #datenight xoRZ"
@jessicaalba: "#axlandslashforever #welcometothejungle @kellysawyer"
@katehudson: "Mother of anarchy is taking her daughters to a little party…. #HappyHalloween @hudsonjeans_pk #hudsons #partytime"
Jessie J donned a gothic-inspired rocker costume for an appearance on British show Celebrity Juice.
Jenny McCarthy as Sandy from Grease at a Halloween Costume Party she hosted with husband Donnie Wahlberg at SiriusXM studios.
@michelletrachtenberg: "#Halloween festivities have begun. #BlackDahlia #ThisIsHalloween"
@janelparrish: "Mrow it's Halloween. Thanks for my catface @samaltamura"
@shenaegrimesbeech: "#casualmondays"
@hrhchriscolfer: "I went to a Halloween party once. It was terrible. #GrumpyCat"
@nayarivera, who dressed as a mail-order bride, wrote: "Always a Dorsey."
@parishilton: "So much fun being Minnie Mouse last night! I love Halloween!"
@kellyosbourne: "Thank you for being the best #RiffRaff to my #Magenta I love you so much @itsryanrandall"
@smashleybell: "Gogo & Joker @jwdasha"
@mollybsims: "Momma's gotta make a livin! #pregogogo #70's knocked up @casamigos"
@katehudson: "Thanks @christianthemua_ for this insanely fun make up! Have a beautiful weekend everyone !"
@itsashbenzo: "Halloween"
@cindycrawford: "Early Halloween! #cher and #gregallman"
@parishilton: "#Bunny"
@joansmalls: "Last night a Ninja found Waldo at a Pizza Truck @derekblasberg #Halloween #HouseParty"
@lucyhale: "This year I go as the Twitter bird."
@hamishbowles: "Preparing for @sarofima #allisonsarofim #stuartparr #halloween #italian #futurism thanks to @thombrowneny and the #makeup #artistry of @nina_park @voguemagazine"
@mariamenounos: "#casamigos #halloween party @rachelzalis your paratroopers are on the way! @giannetos &I are ready!"
Brian Grazer and his costume twin at the Casamigos annual Halloween party in Beverly Hills.