Ambergris

Ambergris, waxy solid formed in the intestines of sperm whales, perhaps to protect them from the bony parts of their squid diets. When obtained from dead whales, it is soft, black, and foul-smelling, but on weathering (as when found as flotsam) it becomes hard, gray, and fragrant, and is used as a perfume fixative and in the East as a spice. The heaviest piece of ambergris found in the intestine of a sperm whale weighed 1,003 lb (455 kg).

See also: Whale.