I've eaten quite a few icky things in Croatia:
Lambs brains - eaten right from the skull (the lamb was roasted on a spit). The taste wasn't bad - very bland, actually, but the texture was much too mushy. Not nearly as disgusting as you would think, though; I'd eat it again. Why did I eat lamb's brains, you ask? When people here roast a lamb, they'll often say that you should eat the part of the animal that you feel you need more of, so I decided to try the brain. The testicles (also called "white kidneys") and eyes are also considered a delicacy by many; I'd rather try my hand at lasik eye surgery, thanks.
If it swims in the Adriatic sea, I've probably eaten it at least once, but I am grosses out by a few of the seafood dishes that are considered specialties here:
Sepia (cuttlefish). I get dry heaves when I smell sepia. I'm not exaggerating. I can't get withing 10 metres of boiled sepia, especially. I can handle sitting near black sepia ink risotto, but that's as far as I'll go. There is another sea-creature similar to Sepia here, called prč (I'm sorry, but I don't know what it's called in English, or what the "standard" Croatian term for it is, if there is one; fish names here vary from town to town, sometimes (usually, actually) greatly, and I really don't think that the names of most seafood items are standardized, as coastal Croatian speech is held in very poor regard in the capital; the capital city is not on the coast. Croatian linguistic politics are nasty, let me tell you.), that I also can't get within 10 metres of.
People here love it, I can't stand it. The smell of brussel sprouts and cauliflower makes me gag, too.
Shark. BBQ shark is great, very tasty. I'm o.k. with octopus, and eel (but I won't eat the skin), too. Dried octopus and dried shark, that I find tough and slightly gross tasting, so I won't be eating that again.
I really, really don't like sea snails. I used to like escargot (the little ones, with lots of garlic, vinegar, parsley and olive oil), but I find that I'm a little repulsed by them lately.
I hate tripe. I hate pigs feet with a passion (I don't like pork in general, and I never make any sort of pork dishes; I will sometimes eat a bit or two just to be polite if someone else serves it to me, though. And I do like boar, I make a mean boar stew, if I do say so myself). I can handle liver and blood sausage, but I don't particularly like either.