Major Spoilers Question of the Day: Inexplicable Cameo Edition

Thanks to MeTV, I often spend my Sunday afternoons in the company of Gilligan, The Monkees and the Brady Bunch, entertaining television that doesn’t distract me from the important work of writing reviews for all the Faithful Spoilerites.  This week was a little different, as my daughter was stunned to see two of those things crossover in the form of Davy Jones’ appearance in season 3 of The Bunch.  It’s an inexplicable cameo, since Davy’s Monkees fame was several years behind him and, though he did have an album come out in ’71, it didn’t include the one song that he sang on the show.  It’s a thoroughly puzzling bit of pop culture nonsense that Davy one-upped the next year with an appearance on ‘Scooby Doo’, leading to today’s Mancunian query…

The MS-QOTD (pronounced, as always, “misquoted”) is aware that “cameo” may not be the right word here, but can’t really think of a better way to describe this sort of guest-shot, asking: What’s the most inexplicable cameo of them all?