Today is Unicorn Day—or what celebrants call "the sparkliest holiday of the year." To honor the mythical horned beast, we bring you the next best thing: a pod of narwhals brandishing their tusks in the Arctic Ocean. Narwhals develop only two teeth, but—in males especially—the left canine can grow into a 9-foot-long spiraled tusk. The tusk juts right through the narwhal"s upper lip, lending the whale the nickname "unicorn of the sea."