Dave Grohl was the guest host of tonight’s episode of Jimmy Kimmel Live, and because it’s Halloween, he did the whole thing dressed in a shockingly realistic post-Late Show Dave Letterman costume. While interviewing guest Kristen Bell, who was dressed as Magnum, P.I., Grohl revealed that his daughters are big fans of Frozen, so naturally, they decided to perform a mashup of “Do You Want to Build a Snowman?” and Metallica’s “Enter Sandman” together. Watch below.

Big Halloween show tonight with Guest Host Dave Grohl Letterman & @ImKristenBell! #MagnumPI #Kimmel #HappyHalloween pic.twitter.com/4LYXVWMSqB

— Jimmy Kimmel Live (@JimmyKimmelLive) November 1, 2017

UPDATE: Here’s the rest of last night’s highlights, including Grohl’s monologue, the full Bell interview, and an Alice Cooper performance backed by Foo Fighters.