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!
Adam Levine and Anne Vyalitsyna dressed up as a rock star wedding  couple for Halloween .
Adam Levine, Anne Vyalitsyna, and James Valentine at the Maroon 5 Halloween  party.
Paris Hilton  dressed up as a princess for Halloween .
Aziz Ansari dressed as Walt from Breaking Bad.
Paris Hilton  showed off her mini ball gown on Halloween .
Jerry Ferrara and Alexandra Blodgett were Eagles cheerleader.
Lauren Conrad  was Minnie Mouse for Halloween .
Breckin Meyer was Batman for Halloween .
Bryan Greenberg was the Brawny man for Halloween .
Paris Hilton  showed off the back of her dress at a Halloween  party.
Lauren Conrad  and Rembrandt Flores were in costume on Halloween .
JC Chasez dressed up for Halloween .
Tara Reid  was out and about for Halloween .
Shaun White wore a red ball gown for Halloween .
Roberto Zincone and Malin Akerman were vampires for Halloween .