The porpoise is all small toothed whale about one and a half metres long. In Norway, the porpoise takes its name, "nise", from an Old Norse word for to sneeze. This refers to the sound of the spout when the porpoise comes to the surface to breathe. The porpoise has a dark grey back and somewhat lighter abdomen with a dark stripe from the corner of the mouth to the pectoral fin. Together with five other species, they form the Phocoenidae family.