If you're anything like me, you're a hopelessly insecure fifty-two-year-old man who is on the radio but can't seem to do that very well. You also grew up reading comic books & that's probably where you first heard the word "zowie." Is "zowie" really a word?
An online dictionary I checked says it is, & defines it as an interjection, which is "used to express keen pleasure, astonishment, approval, etc."
One of my favorite sites, the Online Etymological Dictionary, notes that it's an "expression of astonishment" & dates from around the year 1913, but has no other information about its origins.
Most probably it came about because we humans love to rhyme words for emphasis. You can find many examples - hoity toity, helter skelter, golly wolly, holy moley. The standard English injection for amazement is "wow!" & for extra amazement, we might stretch it out, saying, "Wow-wee!" Add a little rhyme, you can get "wowie zowie!" Eventually "zowie" itself branched off - apparently around a hundred years ago - & became its own interjection.
& good for it! The life of an interjection is hard. Some interjections - like "wow" - choose to play clean, but as time goes by, we have more & more profane interjections, you know the ones I'm talking about: the so-called f-bomb or s-bomb. An expression like "wow" can hardly compete, even if it decides to become a "wow-ie." But you want something novel? almost poetic? maybe slightly European? I give you "zowie."
Please note it does not rhyme with David Bowie; it doesn't even rhyme with Jim Bowie! I have recently been informed that there is a New Zealand pop star called Zowie, but since her real name is Zoe Fluery, I am going to assume that it rhymes with "Zoe" & is therefore not really related to the interjection "wowie." & anyway, it's going to sound weird in that Kiwi accent no matter what.
Why do I think I first heard (or more probably saw) the word in comic books? Look at this:
It's true! The word is often associated with Batman, said often by his sidekick Robin, & probably was uttered a lot during the 1960s television show.
Does this have anything to do with zebras? Maybe. I've never heard a zebra say, "Zowie!" Have you? Frankly I've never heard a zebra say anything. So I'm going to say, reservedly, "In private, zebras say 'zowie' as a statement of astonishment more often than you think."
Zowie! Imagine if that's true!