The meta implications of authors appearing in their TV and movie adaptations is staggering. In simply walking down the street for a brief moment in Mother Night, Kurt Vonnegut is saying "I, the humble Sad Man On Street, actually created this universe. And I have the power to destroy it!"
Not, like, out loud though. He just silently glances at the camera like a sad puppy. But you could tell he was thinking it.
Here are a few more times authors popped up on screen: