I know this wasn't their only appearance but "The Wacky Races" is so much easier to credit than "Dastardly and Muttley in Their Flying Machines" or "Scooby Doo's All Star Laff-A-Lympics." Basically in "The Wacky Races," Dast and Mutt rode around in the Mean Machine in some world-wide race to become the Wackiest Racer. They were baaaaaaad. In "Dastardly...Machines" the pair were sent back to the World War I era where they basically did nothing but pursue a carrier pigeon. They are yet another example of the whole "Villain as Protagonist." But who cares about that?? Let's sing the Pigeon song! Fun fact: It's my all time favorite Cartoon theme song!!! "Stop the pigeon, stop the pigeon, stop the pigeon, stop the pigeon, stop the pigeon, stop the pigeon, stop that pigeon!! How?? Nab him! Jab him! Tab him! Grab him! Stop that pigeon now!!"