 As a voice actor for cartoons he is probably best known for his role as Richie Rich from the Hanna Barbera series "Richie Rich" (1980–1982).He later had regular roles as a voice actor on "Shirt Tales" (1982–1984), "Space Stars" (1981), "Saturday Supercade" as the voice of Dexter on "Space Ace" (1984), "Challenge of the GoBots" (1984), "The Puppy's Further Adventures" (1983), "The Reluctant Dragon" (1981), "" (1984), "Banjo the Woodpile Cat" (1979), " CBS Library" (1980–1982) and "The Get-Along Gang" (1984–86).Marcus has also made several TV guest appearances, including "Trapper John, M.D.