Dijjery-Doo is of a now-extinct canivorous family called hyenadonts. This group survived by living on the Pom Islands, where there was a never ending supply of prey and no competition. His species is the sole survivor of the last ice age, because they were smallest and therefore had more young and therefore could adapt easier. He is named "dijjery-doo" because he sounds like an Aborigianal instrument by the same name. He came to Free Country, USA in a similar manner that The Cheat came (without the egg, of course.) In order to hunt, Dijjery-Doos have adapted large ears for incredibly good hearing and large teeth used to sink into the neck of their prey and hold their windpipe shut, therefore strangling it.