Scooby-Doo and Scrappy-Doo (1979 TV series) threatening cancellation for the show, whose ratings were in decline. ABC was going to choose between two shows-Scooby-Doo or an unnamed pilot from Ruby Spears Enterprises. Therefore, for its 1979–1980 season, "Scooby-Doo" was given a major overhaul, adding the character of Scooby's nephew Scrappy-Doo, voiced by Lennie Weinrib, and changing the name of the show to "Scooby-Doo and Scrappy-Doo". Although still present in these episodes, the characters of Fred, Daphne, and Velma became less essential to the plot and Shaggy, Scooby and Scrappy were the main focus. Marla Frumkin took over Pat Stevens' role as Velma Dinkley towards the end
Scooby-Doo the predominantly skeptic oriented formula to that of most television dealing with paranormal themes, and considered that an adult analogue to "Scooby-Doo" would be a great public service. "Scooby-Doo" has maintained a significant fan base, which has grown steadily since the 1990s due to the show's popularity among both young children and nostalgic adults who grew up with the series. Several television critics have stated that the show's mix of the comedy-adventure and horror genres was the reason for its widespread success. As Fred Silverman and the Hanna-Barbera staff had planned when they first began producing the series, "Scooby-Doo"s ghosts,