In an ultimate prequel to the original Scooby-Doo, Where Are You! the network took the eighth incarnation of the long-running Hanna-Barbera Saturday morning cartoon back in time to when the Scooby gang were pre-teens. A Pup Named Scooby-Doo was the final television series in the franchise in which Don Messick would portray Scooby-Doo before his…