Now here’s an episode that truly went up to 11: in April 1992, Spinal Tap appeared in ‘The Otto Show’. In the episode, Bart and Milhouse attend a Tap gig which quickly descends into chaos. It doesn’t end well for the metallers with “armadillos in their trousers” – their tour bus falls off a cliff. All together now: “we salute you, our half-inflated dark lord!”

