#6 – Narwhal (Monodon Monoceros)

Also known as sea unicorns, these amazing whale species are defined by their “horn”. Since they are of the family of whales, they are sea mammals. They live in the Arctic near Greenland. The “horn” is actually a very long tusk or tooth. This tooth grows and projects through the lip. In some rare cases, two tusks can grow, giving the narwhal two spectacular “horns”.