The family Monodontidae includes two species of marine mammals: the narwhal and the beluga whale. These animals are known for their unique adaptations to cold Arctic and sub-Arctic waters. The narwhal is famous for its long, spiral tusk, which is actually an elongated tooth, while the beluga is recognized for its white color and vocalizations. Monodontidae members are social creatures, often found in groups called pods. They primarily feed on fish, squid, and other marine organisms. Both species are important indicators of the health of their marine environments and face threats from climate change and human activities.