Scooby-Doo
The first episode of "Scooby-Doo, Where Are You!" "What a Night for a Knight" debuted on the CBS network Saturday, September 13, 1969. The original voice cast featured veteran voice actor Don Messick as Scooby-Doo, radio DJ Casey Kasem (later host of radio's syndicated "American Top 40") as Shaggy, actor Frank Welker (later a veteran voice actor in his own right) as Fred, actress Nicole Jaffe as Velma, and musician Indira Stefanianna Christopherson as Daphne. Scooby's speech patterns closely resembled an earlier cartoon dog, Astro from "The Jetsons" (1962–63), also voiced by Messick. Seventeen episodes of "Scooby-Doo Where are You!" were produced in 1969–70. The series theme song was written by David Mook and Ben Raleigh, and performed by Larry Marks.
Scrappy-Doo
Scrappy-Doo is a fictional Great Dane puppy created by Hanna-Barbera Productions in 1979, with the catchphrases, "Scrappy Dappy Doo", "Lemme at 'em!" and "Puppy Power!". He is the nephew of Hanna-Barbera cartoon star Scooby-Doo. Scrappy has appeared in a number of the various incarnations of the "Scooby-Doo" cartoon series. Lennie Weinrib provided his voice for one season in 1979, and from 1980 on it was performed by Don Messick (who also voiced Scooby). In the first live-action theatrical movie, video games, and commercials, he was voiced by Scott Innes. He was created to save the show's ratings which by 1979 had begun to sink to the point of cancellation threats from ABC, who were considering choosing between Scooby-Doo and an unnamed pilot from Ruby-Spears Enterprises, whose pilot Evanier had also written. He successfully boosted the show's ratings and kept the show alive.