Whenever Halloween comes, everyone would either instantly turn into their alter-ego or simply, jump right into the fun of playing dress-up. Anyone has the potential to pull off the wacky ensemble really well or to fail in style. Celebrities, mind you, are no exception. Thanks to Heidi Klum and Ellen DeGeneres, Bette Midler, Katy Perry, Jenna Dewan Tatum, Demi Lovato and …