"Saturday Night Live" musical guest Billie Eilish wasn't the only one to carry a tune on the show's holiday episode.

Host Kate McKinnon called in backup, her former "SNL" co-stars Kristen Wiig and Maya Rudolph, for a few musical skits.

In one bit, the women were joined by "SNL" cast member Bowen Yang as they spoofed ABBA. Complete with over-the-top flashy outfits and "standing close, facing different directions" for most numbers, the mock Swedish group previewed an unreleased 1978 Christmas album featuring "15 brand new Christmas classics and 85 holiday remakes of their existing songs."

Some of the holiday classic included "Fa La La La" to the tune of "Mama Mia," "Who’s That Baby? (It's the Baby Jesus)" and a "wintry take" on "Chiquitita" called "Frostitita."

"Give yourself the gift of ABBA Christmas perfect for everyone from mothers to their gay sons," infomercial host James Austin Johnson said at the end.

The performances continued as McKinnon took the vocal lead in a skit mocking commercials for tampons.

McKinnon was again joined by Rudolph and Wiig for a country music video showing "Tampon Farm," where the menstrual products were produced from trees, the ground and a cranberry bog.

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"Tampon farm / Women making cotton / Cotton for the tampons / Tampons for the blood / Tampon farm / Women with guitars are singing to the tampons / Tampon farm / Sun makes the fires / She hands load the fibers / Into little things of plastic / To go in a jean and the moon makes the menses / And the menses makes the fibers," McKinnon sings in the chorus.

Several female cast members, including Chloe Fineman and Ego Nwodim, were included in the mock commercial. Eilish also showed off her vocals as she joined for a verse.

Eilish later performed "What Was I Made For?" and "Have Yourself a Merry Little Christmas" to cap off the musical night.

Colin Jost roasts wife Scarlett Johansson on 'Weekend Update'

"Weekend Update" hosts Colin Jost and Michael Che held a joke swap on this week's episode, which saw the comics give each other unrehearsed jokes to read aloud during the segment.

In a cruel twist, Che wrote Jost a joke about his wife, actress Scarlett Johansson, to deliver.

"New York State now allows movie theaters to serve alcohol," Jost said as a photo of Johansson and her Marvel film "Black Widow" appeared onscreen. "Which is how I’m finally able to enjoy my wife’s little art movies."

"I’m kidding, honey. I love all of your movies. And if you ask me, you’re an even better ‘Black Widow’ than Coretta Scott King," Jost added, referencing the wife of late civil rights activist Martin Luther King Jr.

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Contributing: Edward Segarra, USA TODAY