Duck family (Disney) strip, Della writes to Donald that the boys had placed a firecracker under their father's chair as a prank and that their father had been sent to the hospital. This was the reason why the boys first showed up at Donald's house. Thereafter the father is generally assumed to have disappeared. In "The Richest Duck in the World", when Scrooge mentions that the few family members he had had disappeared, the boys respond "We know how "that" feels!" Donald's cousin Fethry Duck was created for the Disney Studio Program by Dick Kinney and Al Hubbard and was first used in
Donald Duck Disorder; said theory mentioned can also be found on YouTube. In effect, much like Bugs Bunny cartoons from Warner Bros. the Disney artists had reversed the classic screwball scenario perfected by Walter Lantz and others in which the main character is the "instigator" of these harassing behaviors, rather than the butt of them. The short 'Clown of the Jungle' (1947) very much feels like either a Daffy Duck or a Woody Woodpecker cartoon. The post-war Donald also starred in educational films, such as "Donald in Mathmagic Land" and "How to Have an Accident at Work" (both 1959), and made cameos