The Scooby-Doo/Dynomutt Hour debuted on September 11, 1976. After two months, an additional 30 minutes were added to the hourlong series (to accommodate repeats of the first two CBS seasons of Scooby-Doo, Where Are You!), becoming the 90-minute Scooby-Doo/Dynomutt Show, which is how it remained from December 4, 1976, to September 3, 1977. Like many animated series created by Hanna-Barbera in the 1970s, the show contained an inferior laugh track created by the studio.