Fish of the family “Tetraodontidae” contain lethal amounts of the poison tetrodotoxin in their internal organs, particularly the liver and gonads and also the skin. When in danger, the fish balloon fills its stomach with water and takes a round form to frighten its pursuer. Furthermore, there are hidden spikes that jut with bulging body becomes prickly and difficult to swallow by the attacker.
In Japan a dish called Fugu is prepared from this fish. Only specially licensed chefs can prepare and sell fugu, and the consumption of the liver and ovaries is forbidden. But because small amounts of poison cause particularly desirable sense of language resembling mild numbness and tingling that lasts about 15 seconds after ingesting the piece of meat, these parts are considered the most delicious by some gourmets. If it does not pass up to 15 seconds you can consider yourself dead.
Each year a number of people die because they underestimate the amount of poison in the edible parts of the fish. The poison paralyzes the muscles, the victim stays fully conscious, and eventually dies from asphyxiation. Still there’s no antidote found and the standard medical approach is to try to support the respiratory and circulatory system until the effect of the poison pass.