The older members of my family (non-Jewish) eat a soup made with duck's blood.
Those, uh, gourmet delicacies could be prepared according to kosher specifications.
Calves foot jelly! Now there's a kosher "delicacy" I could live without.
Alouette will know better about the oysters, I've read they're not but I don't know why. Fried rattlesnake is out though.
My father ate a dish he called pitzah which consisted of fried brains and garlic. I've later heard pitzah is garlic and cows feet, so it's likely anything you can tell the butcher is for the cat, fried with garlic.
Duck's blood soup, yuk, though I have relatives that eat whitefish soaked in lye (lutefisk-a winter thread) so to each their own.
I've actually had the "pleasure" of eating kosher turkey "oysters" in the Jerusalem shuk. Taste rubbery. Not something I would repeat.
No problem with fried calves brains. I've eaten them too.
On the other hand, the ducks' blood would be a problem-- blood in general ain't kasher.
I've also eaten bison (yum yum), venison (unremarkable and leathery-- tastes a little like liver), quail (absolutely wonderful, I hope I get to dine on it again some day). Never had goat, but I'm looking forward to it the next time I go to Israel.