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.
Scooby-Doo
"Scooby-Doo" itself would be an influence on many other Saturday morning cartoons of the 1970s. During that decade, Hanna-Barbera and its competitors produced several animated programs also featuring teenage detectives solving mysteries with a pet or mascot of some sort, including "Josie and the Pussycats" (1970–71), "The Funky Phantom" (1971–72), "The Amazing Chan and the Chan Clan" (1972–73), "Speed Buggy" (1973–74), "Goober and the Ghost Chasers" (1973–74), "Jabberjaw" (1976–78), "Captain Caveman and the Teen Angels" (1977–80), among others.