Dave Grohl dressed up like David Letterman and guest hosted Jimmy Kimmel Live on Halloween! One of the most talked about moments of the night (other than the Letterman costume, which was spot on), was his interview with Kirsten Bell, who was dressed up like Magnum P.I.
Grohl told Bell that his daughters were big fans of the movie Frozen, so she sang "Do You Want to Build a Snowman" and that turned into a mashup with Metallica's "Enter Sandman" wish Dave on drums. Check out the epic video below.