Billie Eilish was almost unrecognizable, trying to keep a low profile, as she arrived for the Saturday Night Live after party in New York.

The hitmaker, who will turn 22 Monday, was the musical guest for the final episode of 2023 with SNL alum Kate McKinnon hosting her old haunting grounds for the first time since leaving the show in 2022.

The What Was I Made For singer bundled up in a black, red and white athletic sweater with the number 52 on it, and an oversized red, black and white coat.

The Grammy winner wore wide leg jeans and white sneakers.

Billie covered her shoulder length dark hair with a black toque with a red star, which was then covered with a black billed hat.

Billie Eilish was almost unrecognizable, trying to keep a low profile, as she arrived for the Saturday Night Live after party in New York, bundling up in a red and black coat, an athletic sweater and covering  her head in a toque and billed hat

The Ocean Eyes artist wore silver dangling earrings and square sunglasses.

In her Instagram Stories, the Oscar winner shared photos of two promo posters for her appearance. On one she wrote, ‘Peak Life Experience, Thank You,’ and signed her name.

On the other she penned, ‘I aged 5 years this week (it’s okay tho) Nothing will ever beat this. I wanna do it all again!!!’

Billie performed the Barbie hit What Was I Made For for her first number which was introduced by Kate and Barbie director Greta Gerwig and Have Yourself a Merry Little Christmas for her second.

The Lovely singer winner celebrated the successful episode alongside guests including Claudia Sulewski, Questlove, Phoebe Bridgers, and Jon Hamm and his wife Anna Osceola.

Kate McKinnon, 39, kept warm in a black wool coat over what appeared to be a black suite with a white button down shirt.

The Barbie actress wore black and white Converse high tops with the otherwise polished look.

The comedian styled her blonde hair in a wavy bob and wore natural looking makeup with a light pink lip, showcasing her flawless complexion.

The Grammy winner was the musical guest for the December 16 episode, performing her Barbie hit What Was I Made For and the holiday classic Have Yourself a Merry Little Christmas

In her Instagram Stories, the Oscar winner shared photos of two promo posters for her appearance. She wrote, ‘Peak Life Experience, Thank You.’ On the other she penned, ‘I aged 5 years this week (it’s okay tho) Nothing will ever beat this’

SNL regular Sarah Sherman, 30, lit up the night, wearing a multi-colored coat in shades of bright green, yellow, red, and blue.

The Nimona actress tied a red and white scarf around her neck and wore a black t-shirt.

She donned blue and black striped pants with a cuff ending mid-calf.

Kate McKinnon, 39, kept warm in a black wool coat over what appeared to be a black suite with a white button down shirt. The Barbie actress wore black and white Converse high tops with the otherwise polished look

SNL regular Sarah Sherman, 30, lit up the night, wearing a multi-colored coat in shades of bright green, yellow, red, and blue. The Nimona actress tied a red and white scarf around her neck and wore a black t-shirt, blue and black striped pants and ankle boots

SNL alum Jason Sudeikis, 48, kept his look sleek but simple, wearing a black Nike hoodie with an orange basketball player logo, black slacks and orange and white Nike sneakers with black laces

The funny lady stepped out in thick soled black ankle boots with yellow socks, revealing just colorful tattoos on each leg.

The comic placed a bright red beanie over her dark hair and carried a large black bag.

SNL alum Jason Sudeikis, 48, kept his look sleek but simple, wearing a black Nike hoodie with an orange basketball player logo, black slacks and orange and white Nike sneakers with black laces.

The Ted Lasso star wore a scruffy beard with evidence of new mustache growth and completed his look with a black billed hat.