We've talked before about how Pufferfish is the ultimate Japanese delicacy. However, one does not simply cook Pufferfish. Japanese cooks have to go through 3 years of training, because of how precise the cooking of the fish has to be.
Pufferfish poison is resistant to cooking, and there is no known antidote for it. This means that the slightest error in cooking can kill the person eating it. The chef has to remove the liver, ovaries and intestines of the fish in order to remove the poison. After the three years of training, the chef faces a final test: cook and eat their own plate of Pufferfish. I bet there are only two grades: pass or die.
Still, it's reported that 50 to 100 people die each year from Pufferfish poisoning. In many ways, the risk is what makes it such a delicacy. It explains why it's said that the best chefs can leave just enough poison in the fish to feel a little harmless numbing when you eat it!