Creator Joe Murray does the voice of Ralph.
In an attempt to get out of his career as a cartoonist, Ralph also created the intentionally bad cartoon Wacky Delly to have it immediately cancelled (Instead, the show became a runaway hit, much to his dismay). He created a cartoon called The Fatheads. However, in a later episode, he and Ed finally reunited and ended their feud. He was disowned by Ed for not wanting to work for Conglom-O, so he went to Holl-o-Wood to become a cartoonist.
Filburt Shellbach: Rocko's other best friend, a neurotic turtle started out as a background character and became a main character in the second season.Though he is normally portrayed as being jobless, he has worked in a number of professions including a waiter at a coffee shop, a salesman at a tree farm, and a security guard at Conglom-O (which induced him to go insane). Heffer Wolfe: Rocko's best friend, a happy-go-lucky and not-too-bright steer whom he met in high school.
A running gag is that other characters assume that Rocko is another kind of animal (usually a rabbit or a dog), and then he goes into a lengthy (and often unconvincing) explanation that he is a wallaby. Rocko: a wallaby who has emigrated to the United States from Australia works at "Kind of a Lot o' Comics" (although he had other jobs, including being a product tester at Conglom-O and being an underwear model).