Billie Eilish is helping fans close out 2020 with a giggle by sharing video footage of her all drugged up after wisdom teeth surgery last year.

The Bad Guy hitmaker was taking part in the viral "post a picture of" social media challenge when one user asked Billie to share old footage of herself following her dental procedure.

The pop star obliged on Tuesday and offered up clips of herself wide-eyed and loopy as her mother drove the recovering singer home.

In one video, Billie's mum can be heard saying: "Don't open your mouth when it has gauze in it. You don't want it to fall out!"

"I'm not gonna choke on it," Billie replies, as she realises her loved ones are filming her on a phone.

As the teenager sticks a finger in her mouth and complains: "It's bloody," her musician brother Finneas is heard laughing in the backseat and quipping, "Of course it's bloody. Your mouth is bleeding. We're gonna spit out your gauze when we get home!"

Meanwhile, Billie also used the challenge to share the full story behind the green and black mullet hairstyle she first rocked in November 2019, admitting it was the result of a dye job gone horribly wrong.

Asked by one follower to post a photo of "the most f**ked your hairs been (sic)", she uploaded a video of herself checking out her hair disaster in her bathroom, and advised followers: "don't trust just anyone who says they're good with color. my hair continued to fall out in chunks for the next two months after this".

Circling her shortened green locks in a picture from the 2019 LACMA Art + Film Gala, she explained, "these pieces were just all the hair that got burnt off that had grown back. while everyone thought i got a mullet (sic)".