Don Messick
Donald Earl "Don" Messick (September 7, 1926 – October 24, 1997) was an American actor. He was the voice of Scooby-Doo in Scooby-Doo, Bam Bam Rubble in The Flintstones, Astro the Dog in The Jetsons, Muttley the Dog in Wacky Races, Papa Smurf in The Smurfs, and as Dr. Quest in Johnny Quest.