narwhal: [17] The narwhal, a small arctic whale with a long unicorn-like tusk, is whitish in colour, which evidently reminded Viking seafarers somewhat morbidly of a corpse, for they named it in Old Icelandic nāhvalr, literally ‘corpse whale’. In Danish and Norwegian this became narhval, and English took it over and partially anglicized it as narh whale. Over the centuries this has contracted to narwhal. [narwhal etymology, narwhal origin, 英语词源]