Blow fish:
a poisonous chemical called tetrodoxin found in its skin, blood, ovaries and especially its liver. This is a toxin that makes cyanide look like Aspirin - one match-head worth can kill thousands. Just touching a fugu the wrong way can be deadly and, appropriately, our multi-course feast started with a salad made with the skin.

Most reports of fatal fugu poisoning concern fishermen who, having had the fortune to catch a fugu, lacked the foresight to throw it back. They attempt to "sashimi" the fish themselves and pay the ultimate price. Not, however, before experiencing a numbing of the lips and tongue, a growing paralysis of the body, headaches, gastric pain, vomiting and convulsions. It's not all bad though, you do get the consolation of a light and floaty feeling. After 4-6 hours of this, death occurs. There is no known antidote.

http://www.american.edu/TED/blowfish.htm

The should have saved it until the end of the meal. That way, while you are dying, you will have something to spew.