Often served as sashimi, fugu is possibly the most exotic and dangerous food known to the world. If not properly prepared, it really can cause death (an episode of the The Simpsons provided a public service by alerting its fans to the inherent dangers of fugu). The most toxic parts of the fish are treated as hazardous waste.
Fugu chefs in Japan are strictly licensed and highly trained to prevent accidents (in other words, don't try this at home), so fugu offered in restaurants is safe for consumers. Though true connoisseurs can appreciate subtle flavors of the fish, many find it bland. That being said, some highly trained chefs include a tiny bit of the toxin when they serve fugu. The toxin will create a prickly, numb feeling on the tongue. Fugu is forbidden to the Emperor of Japan, for obvious reasons.