Discover how skeletons, organs, nerves and muscles fit together inside your favourite animals with detailed, scientific pictures that reveal more than meets the eye. From the mighty to the mini, prepare to be amazed at what these beasts are made of.

• Uncover facts about blue whales, whose arteries are so big that a human could swim through them.
• Find out how many hearts an octopus has and how it uses them to survive on the sea floor.
• Look more closely at camels to uncover exactly what's going on inside their humps.
• Special feature pages break down the basics of skeletons, organs, muscles and more.