Koala

Built for Climbing: In the wild, koalas are found exclusively in the large eucalyptus forests of eastern Australia, where they spend almost their entire lives in trees. Their bodies are very well-adapted to the life of a tree-dweller. For instance, each of their forepaws has three fingers with long, sharp claws for climbing and two opposable fingers for grasping branches. Each of their hind paws has two climbing fingers, one grasping finger and two grooming fingers, the latter of which specialize in removing twigs and ticks that get tangled in their dense fur.

A Barrier of Fur: Their thick, wool-like fur is the perfect camouflage. The gray to light brown color matches the bark of eucalyptus trees, concealing the fleshy koalas when predatory birds are on the prowl. Their fur is so thick and cushiony that koalas can sit on pointy branches for hours and hours and never feel pain.

A Toxic Diet: Koalas feed almost exclusively on eucalyptus leaves, which are highly toxic. Of the approximately 350 species of eucalyptus, they can digest only 20 and prefer a mere five.