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Most convoluted cameo:
Michael Jackson on The Simpsons
The Simpsons, for its third season premiere, featured a large white mental patient who thought he was Michael Jackson and sounded surprisingly like Jackson, although the credits at the end of the episode credited John Jay Smith. Who is John Jay Smith? No one knows. Because of some arcane contractual reasons, Simpsons creator Matt Groening and his writing staff have never been able to confirm Jacksons participation in the episode. Although theyve strongly hinted at it through the years.