Narwhals

Narwhals are highly-endangered members of the whale family. They're about the size of a small whale, and live only in the coldest of the arctic seas. Their "horn" is somewhat of a mystery, it's purpose unknown but thought to measure water temperature and chemical concentrations. The spiralling horn is actually the top-left incisor in a narwhal's mouth, which spirals outward to lengths of over 9 ft. Subhanallah.