15 Billie Eilish Halloween Costume Ideas For All You Bad Guys

The music video for "Bad Guy" is possibly Billie's most iconic video to date — it's a musical and visual masterpiece. She has so many outfit changes throughout the song, but the yellow sweatsuit is one of the most notable.

What to wear: An oversize yellow hoodie and matching sweatpants with yellow sneakers; don't forget to pull up the hood.