Imagine Will Ferrell singing Beyonce's "Drunk In Love" -- OK, not that easy to picture? Well, after watching his enthusiastic lip-synced version -- it's honestly hard to forget.
Ferrell also took on Idina Menzel's "Let It Go" from "Frozen," while Kevin Hart opted for Katy Perry's "Roar."
Fallon tapped Drew Barrymore as backup for his rendition of "Time of My Life" from "Dirty Dancing."
Check out Ferrell -- in all of his sweatshirt-wearing glory -- below: