Who's Scooby-Doo?

Who's Scooby-Doo? is the first part of the fifth episode of The Scooby-Doo/Scrappy-Doo/Puppy Hour.

Premise
The guys enter their Super Pizza Maker in the Teenage Science Fair, but someone else has entered a Personality Changer, and Shaggy and Scooby's personalities get switched and then someone steals the machine.

Cast and Characters

 * Don Messick as Scooby-Doo and Scrappy-Doo
 * Casey Kasem as Shaggy Rogers