 Boris Karloff, the original voice of the Grinch, had died in 1969), while Mason Adams took over voicing the Cat in the Hat from the late Allan Sherman, who died in 1973.Since Friz Freleng was absent from production on "The Pink Panther" special "" due to his departure from DePatie–Freleng Enterprises to return to Warner Bros.Animation, this was the only other fully animated DFE production to be made by Marvel Productions and one of the last DFE cartoons Freleng was involved in.