Ambergris is a waxy substance that's very approximately a sperm whale analogue of owl pellets -- it helps encapsulate bony squid bits and gets digestively eliminated. Historically it was used as a perfume ingredient.

I think it'd be neat to have a small sample, but apparently the sale and trade of ambergris was categorically banned by the Endangered Species Act of 1972. Bit of a shame since chunks of the stuff occasionally wash up on beaches and can be collected without getting anywhere near a whale.