glass frog, narwhal,axolotl (Animal facts)

The glass frog has transparent skin on its belly, allowing you to see its internal organs.

The narwhal, often called the "unicorn of the sea," has a long, spiral tusk that can reach lengths of up to 10 feet.

The axolotl, a salamander from Mexico, can regrow lost limbs and even parts of its heart and brain.