Halloween party with Celebrities

Actor Neil Patrick Harris (L) in costume poses with unidentified guest at Playboy Magazine founder Hugh Hefner's annual Halloween Party at The Playboy Mansion in Los Angeles

Paris Hilton poses at Playboy Magazine founder Hugh Hefner's annual Halloween Party at The Playboy Mansion in Los Angeles in this OctoberPlayboy Magazine founder Hugh Hefner (L) and Crystal Harris pose together at Hefner's annual Halloween Party at The Playboy Mansion in Los Angeles in this October