The name "narwhal" means "corpse whale" because they tend to float motionless at the surface for long periods of time, but this whale is generally recognized because the male has a long spiralling tusk. he narwhal thus has the nickname "unicorn of the sea", and may in fact be the source of unicorn legend. The horn is actually a modified tooth and is probably used much like deers use their antlers- to compete with other males for females. They have short pectoral fins and a slight hump instead of a dorsal fin. They eat fish, quid, and krill, and live in the extreme Arctic, rarely farther south than 70 degrees north. Their main enemy is man, especially the Inuit who kill many but only take about half of what they kill. 1 in 500 males have a double tusk, and all tusks spiral in a counter-clockwise direction. Most single tusks are on the left.