Ambergris from the North Sea. Ambergris (/ˈæmbərɡriːs/ or /ˈæmbərɡrɪs/, Latin: ambra grisea, Old French: ambre gris), ambergrease or grey amber, is a solid, waxy, flammable substance of a dull grey or blackish colour, produced in the digestive system of sperm whales. Freshly-produced ambergris has a marine, fecal odour.