Multiple behaviors were observed that indicate narwhal tusks — like Swiss Army knives — serve as multi-purpose tools. While they likely evolved for sexual selection (males use their tusks to compete for females), they also appear to be integral in hunting and play.

The narwhal (Monodon monoceros), an iconic whale of remote Arctic waters, is widely known for its long, spiral tusk, which is really an elongated tooth. The tusk, which is predominantly found in males and can grow up to 10 feet long,

With a fabled ability to purify tainted water or heal ailments, the narwhal's spiraling tusk was highly coveted during the Middle Ages when it was mistaken for a unicorn's horn.