I'm an emetophobe, agoraphobe, terrified of heights...but I find that those are more or less common.
But I have one random one that's followed me since early childhood and it's so random and silly it makes me laugh even though it still stalks my nightmares.
I'm scared of fish. When I was little, going to the aquarium was my favorite thing ever...until I came face to face with a "special exhibit," a visiting fish if you will...it even had the most benign name you can think of: a unicorn fish! For whatever reason I freaked the heck out at the sight of it (I still think they're horribly creepy tbh) and ever since them, certain fish have made me feel uneasy. Weirdly, all the fish that sent me into a panic as a kid had weird facial protrusions - I was scared of those unicorn fish (google it and you can see how they got their name!) and swordfish. I had a book about Big Bird and the Sesame Street gang going to the aquarium and there was a giant picture of a swordfish...my parents ended up putting masking tape over the...sword? I don't know if that part has a name. The long pointy part of its face. I'm more or less over the swordfish thing, but I still don't like unicorn fish...and goblin sharks, forget it.
Even weirder is that I still love fish and aquariums to the point of fanaticism, and my dad and I were drawing up plans to install a reef tank in the apartment before he passed. But the love and enthusiasm come with anxiety and a feeling of being smothered. I have nightmares about fish all the time. Yet my biggest dream in life is to go to the GA Aquarium and see the whale sharks in person!
I don't know; I thought some people might find this a little funny. I know how draining being phobic about things is. I think sometimes laughing at ourselves helps. I mean, fear of heights at least makes sense...I don't think anyone's ever been maimed by a tropical fish!