Either something you've tried, or something you've heard of but would quite frankly rather starve to death than ever eat.
I'll start with three...
Casu marzu cheese, which contains live maggots [en.wikipedia.org]
Canned whole chicken [oddee.com]
Canned pork brains in milk gravy (check out the cholesterol level on what must be the least kosher food ever invented) [static.neatorama.com]
Tripe has a weird texture.
Sorstrummin from Sweden is canned fermented fish. From Wikipedia:"...According to a Japanese study, a newly opened can of surströmming has one of the most putrid food smells in the world, stronger than similarly fermented fish dishes from Japan and Korea..."
My cousin told me of his youth and a day he and his 11 yo mate went walking with the hunting dog on the Lake District mountains in the NW England. They walked so far that they ended up having to carry the dog. Returning to his mate's home he was welcomed in by his mate's mother. She sat them at the farmhouse kitchen table, slapped a one and half inch slab of farmhouse bread in front of each of them and ladled on to it a northern dish called " cheese and onion ".
Now my cousin had never in his life, after a first attempt, been able to eat this delicacy without vomiting.
#MyRecipe: The recipe is simple simply adjust quantities for the number of people eating - a lot of onions are halved and thrown into a large saucepan. A large block of cheese, the tastier the better - a favourite was Lancashire tasty cheese (that was the cheese that if left on the sideboard had an aroma that would, through the closed front door and at thirty paces, make the eyes of passersby water!) was sliced and added to the pan with sufficient milk to cover the whole. It was then boiled until the onions became soft and translucent, the cheese soft slabs and the milk reduced to a thick white sauce consistancy.
Well according to George he was so hungry and knowing in a Lakeland subsistance farm the only food was that on the table he had no alternative but to eat it.
He told me the story about 50 years after it happened and I can still remember even though it is now at least fifty years since he told me, the gleam of remembered ecstasy that he still had for his satisfaction at that simple meal and its assuaging of his hunger pains all those years previously.
A good memory for me and perhaps a timely reminder for many people.
I was offered snake once in China, did not appeal to me at all! I don’t like Pigs feet, far too much fat and grizzle, don’t like hearts or Haggis but Generally speaking I’m quite opened minded about food. I forgot to mention Water Melon, makes me feel sick if I try just one piece. Don’t know why, if it’s just the juice in a glass I will drinkit, no problem.