Onomatopoeia is an amusing thing. We have a need to translate the sounds we hear into written words, and everyone does it differently.
Dogs, for instance, make so many varying sounds that the word we settled on in English is bark. Really? A multitude of sounds and the word we settle on is the stuff on the outside of a tree. Have you ever heard a dog say "bark"? Even my one year old knows that different sized dogs say different things, but that is probably because her favorite book is “Moo, Baa, La La La” by Sandra Boynton, which tells her that “Rhinoceroses SNORT and SNUFF, and little dogs go RUFF RUFF RUFF! Some other dogs go BOW WOW WOW, and cats and kittens say MEOW!”
In Finnish, a dog says “vuff.” In Japanese, they say "wan." Greek dogs say “gav gav.” In French, dogs say “ouah ouah,” and the tone of voice changes depending on the size of the dog. We all have unique ways of translating the sound they make. Some are closer to the actual sound than others. (Nice going, English.)
When I was a kid, I loved the movie Dumbo, and paraded around the house making my own version of an elephant noise: “Trumpeeet!” (I was an adorable child.) And even though I don’t like Family Guy, one scene I do enjoy is the one where Stewie is playing with the European See & Say. He disagrees with every sound (“The Monkey goes: ‘Macaque!’” “Oh no, no, no! It does not!”) until he gets to the elephant: “The Elephant goes: “Voooamp!” at which he shrugs and says “Eh, kinda.”
I’ve never actually met a fox, but I’ve read lots of different ways to onomatopoeize the sound it makes. “Yip,” “bark,” “scream,” and “cry” are all sounds attributed to a fox. Maybe it makes a different noise depending on the situation it’s in, like when you can tell your dog’s mood by listening to its scared whining, happy barking, or angry growling. Maybe a fox just has a wider vocabulary than most animals.
But I’m moderately certain that no one has ever heard a fox say “Wa-pa-pa-pa-pa-pow!” or “Hatee-hatee-hatee-ho!” or seen it try to use Morse code.
(My favorite part, aside from the fact that this song is super-catchy and kind of a parody of all popular music, is the grandfather trying to read the crazy onomatopoeia to his grandkid. Hilarious.)