Snoopy is credited with writing a Batman story? It’s true. In 1980, writer Len Wein and artist Walter Simonson wrote a two page story called ‘Once Upon A Time’ that appeared in Detective Comics 500. The story featured Batman fighting and capturing a group of robbers. The narration of the story comes from Snoopy’s “It was a dark and stormy night” story he tried publishing. The Grand Comics Database decided to add Snoopy (and Charles Schultz) to the writing credits, making it Snoopy’s first published work.