The first time I read about ambergris was in Encyclopedia Brown. I didn’t believe it was real, that perfume was made from whale vomit, until I looked it up at the library. It’s one of those things that you remember for the rest of your life.
Hyraceum is made from petrified hyrax droppings, while civet oil, musk, and castoreum come from the anal glands of civets, deer, and beavers respectively.