ALEXJR / BACKGRID Billie Eilish is having a rootin’, tootin’ good Halloween! The 21-year-old singer nailed the spooky season with a fun cowgirl costume for this year's celebrations and was ...

“And, of course, without any of them communicating with each other, they all dressed up as Billie Eilish. It was very funny.” The best Eilish costume of the night, however, went to the pop ...