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 Animation and Hanna-Barbera (by then a subsidiary of Warner Bros. following the merger of Time Warner and Turner Entertainment in 1996) began producing one new "Scooby-Doo" direct-to-video movie a year beginning in 1998. These movies featured a slightly older version of the original five-character cast from the "Scooby-Doo, Where Are You!" days. The first four DTV entries were "Scooby-Doo on Zombie Island" (1998), "Scooby-Doo! and the Witch's Ghost" (1999), "Scooby-Doo and the Alien Invaders" (2000), and "Scooby-Doo and the Cyber Chase" (2001). Frank Welker was the only original voice cast member to return for these productions. Don Messick had died