We knew that the Foo Fighters’ Dave Grohl would be appearing on The Muppets, and we knew (and saw) that he would be having a drum-off with Animal. What we didn’t know until the episode aired is that he would be playing “Learn to Fly” with Dr. Teeth and the Electric Mayhem.  Granted, it’s a shorter version of the song, mixed in with some plot involving Gonzo, but if you’re a Foo completist, you’ll want to see this – especially since it gives another look at the drum-off. Now let’s get a metal band on the Muppets; we suggest having Mayhem play with the Electric Mayhem.