5. Narwhal: The Unicorn of the Sea
The narwhal has earned its nickname as the “unicorn of the sea” thanks to its remarkable spiral tusk. This tusk is actually a super-sized tooth, packed with sensitive nerves that help the narwhal sense its icy Arctic environment. Researchers believe the tusk may also play a role in mating displays and navigation beneath the frozen seas. The narwhal remains one of the most mysterious and enchanting mammals in the ocean. See details here.