Scooby-Doo the series and the billing, in an attempt to boost "Scooby-Doo"s slipping ratings. The 1979–80 episodes, aired under the new title "Scooby-Doo and Scrappy-Doo" as an independent half-hour show, succeeded in regenerating interest in the show. Lennie Weinrib voiced Scrappy in the 1979–80 episodes, with Don Messick assuming the role thereafter. Marla Frumkin replaced Pat Stevens as the voice of Velma mid-season. As a result of "Scooby-Doo and Scrappy-Doo's" success, the entire show was overhauled in 1980 to focus more upon Scrappy-Doo. At this time, Scooby-Doo started to walk and run anthropomorphically on two feet more often, rather than on
The Scooby-Doo Show of which, "The Chiller Diller Movie Thriller", guest-starred Scooby-Doo and Scooby-Dum's distant female cousin, Scooby-Dee), plus reruns from the 1976–1977 season. The name of the block was changed to "Scooby's All-Stars" for the 1978–1979 season, when the program was shortened to an hour and a half, after the cancellation of "Dynomutt". 16 half-hours of "Scooby-Doo" (featuring just the original five characters) were produced this season, and began airing earlier in the morning before the "Scooby's All-Stars" block as a third season of "Scooby-Doo, Where Are You!" in September. "Scooby's All-Stars" instead aired reruns of the 1976 and 1977 episodes for