I was out of town yesterday, and didn't get to see this past Sunday's edition of Red and Rover until this afternoon. But there's a big problem! The quote is indeed from The Wizard of Oz — but not the book. It's taken directly from The Movie. Roughly ninety-nine percent of the dialogue in The Movie does not come from the book. Most likely that quote was written by Noel Langley, but with the number of writers involved in producing that script, it would be difficult to determine who actually wrote it without access to MGM's archives. Still, it's a cool comic!