Scooby-Doo and the Alien Invaders Original Production Cel Signed by Bob Singer: Scooby-Doo and ShaggyScooby Doo, Shaggy MEDIUM: Original Production Cel SIGNED: Bob Singer SIZE: 10. 5"X9" PRODUCTION: Scooby Doo and the Alien Invaders SKU: IFA5094 ABOUT THE IMAGE: The Hanna Barbera cartoon, Scooby Doo, Where Are You? was launched in 1969 and has had the longest run of a cartoon series. Over the years its been in 19 TV series (on CBS, ABC, the WB, Cartoon Network and Boomerang) and more than 40 animated films and two live action movies; one grossed $275