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
Scooby-Doo and the Pirate Ghost", followed in 2009. The Mystery Machine has been used as the basis for many die-cast models and toys, such as from hotwheels. By 2004, the various "Scooby-Doo" merchandise had generated over in profit for Warner Bros. Licensed merchandise also sold in 2015, in 2016, and in 2017. During its four decade broadcast history, "Scooby-Doo" has received two Emmy nominations: a 1989 Daytime Emmy nomination for "A Pup Named Scooby-Doo", and a 2003 Daytime Emmy nomination for "What's New, Scooby-Doo"s Mindy Cohn in the "Outstanding Performer in an Animated Program" category. Science advocate Carl Sagan favorably compared