The guys of Maroon 5 got in on the Halloween party hosting action last night by gathering their friends at the Hollywood Forever Cemetary for a bash. Frontman Adam Levine and his girlfriend, Anne V, were in their '80s finest going as a "rock star wedding couple," and Lauren Conrad looked adorable decked out as Minnie Mouse. She tweeted about how her friend Kristen Ess actually created the mouse ears out of Lauren's own hair! Paris Hilton was a princess while How to Make It in America star Bryan Greenberg was a hot Brawny man! Parks and Recreation funny guy Aziz Ansari was fresh off a college tour to mingle with the crowd decked out as Walt from Breaking Bad. Adam and his band's event was just one of the many that brought out celebrities in Halloween costumes on both sides of the country!