Narwhal
Context
A medium-sized toothed whale known for the long, spiral tusk extending from its upper jaw
Explanation
Inhabiting Arctic waters, narwhals are known for their distinct tusk, which is actually an elongated canine tooth and can grow up to 10 feet long
Applications
Narwhals are often called the 'unicorns of the sea' due to their tusk.
Narwhals use their tusks for sensing their environment and possibly for mating rituals.
Narwhals are social animals, often found in groups of 15 to 20 individuals.