- "Ambergris. Noun. A grease-like product of the sperm whale's digestive tract that is used as a base in the finest perfumes."
Ambergris is a precious material which comes from the digestive tract of sperm whales, which is a base ingredient in fine perfumes. In its raw state however, ambergris is a putrid, waxy substance that is said to smell like "freaking porpoise hork".
After Kif made the famous whale Mushu throw up by feeding him bad fish in order to retrieve the watch the whale had swallowed, he was covered in the substance, and imprisoned until he returned the aquarium's property. It came a surprise to Kiff to find out that the property in question wasn't the watch, but the ambergris itself, so in order to save the bother of scraping it off him he shed his skin instead, keeping some of the ambergris in the process, to turn into a perfume for Amy.