It’s been a few months since Billie Eilish made her triumphant return to black hair with super-bright roots — the neon green of yesteryear is now fiery red — but as of this weekend, she’s already found two reasons since this summer to sport a blonde wig. First, for her heartbreakingly beautiful Barbie-inspired “What Was I Made For?” music video, and now, for a deep-cut Halloween costume.

Billie was spotted attending Kendall Jenner’s Halloween party at the Chateau Marmont over the weekend dressed as a cowgirl, wearing a blue and white gingham shirt, brown pants and matching cowboy hat. Under the hat wasn’t the singer’s usual pitch-black and vibrant red hair but, instead, wavy, strawberry blonde hair with long, side-parted bangs.

This wasn’t just any cowgirl costume, though. Fans of 1960s westerns might recognise the shirt or the hairstyle and colour as that of the iconic Jane Fonda in the 1965 film Cat Ballou, in which she played the title role. This was confirmed by Billie’s Instagram story, in which she shared not only a few photos of herself in costume but also a few photos of Fonda as Cat Ballou.

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Needless to say, if Cat Ballou was ever a household name, it isn’t anymore, but at some point in her young life, Billie Eilish became enough of a fan to recreate the lead’s look for a fantastic — if not instantly recognisable — Halloween costume. So although most of Billie’s fans probably haven’t seen the comedy about a vengeful daughter of a rancher, we have a feeling plenty will want to watch it now.