Billie Eilish

Could there be a collab in their future?

They're hardcore in their own ways.

Talk about a girl crushcrushcrush.

Grohl was one of two special guests Eilish invited onstage at her headlining L.A. show.

We're rockin' around the Christmas tree and into a long list of rock stars who are celebrating their birthdays this month.

See which rock and alternative acts have been nominated.

There's also prominent names such as Motorhead and Misfits.

And it's not the song she performed with Hayley Williams at Coachella.

Williams previously retired the track from Paramore's live sets in 2018.

The late drummer was initially meant to perform with Foo Fighters at the 2022 Grammys.