when ABC drops Scooby-Doo following the unfinished business of "the 13 Ghosts" arc, they had other things in the form of three full-length movies for the H-B Superstars 10 package. The first of which: When Shaggy inherits his uncle's mansion, he encounters ghostly tenants and asks the Boo Brothers for help. featuring Don Messick as Scooby-Doo and Scrappy-Doo, and Casey Kasem as (his nephew) Shaggy. Supervising Director: Ray Patterson. Written by Jim Ryan. Producer: Kay Wright • Executive Producers: William Hanna and Joseph Barbera. Music Composed and Conducted by Sven Libaek • featuring the Main Theme by Bill Hanna. from Hanna-Barbera Productions; Syndicated by Worldvision Enterprises, Inc..