Koala

Koalas are nocturnal marsupials famous for spending most of their lives asleep in trees. This sedentary lifestyle can be attributed to the fact they have unusually small brains and survive on a diet of nutrient-poor leaves. The koala's leaf of choice is eucalyptus, a particularly fibrous and highly toxic plant. Luckily for koalas, what they lack in brain power they make up for in the length of their intestine, which measures a colossal two metres and is packed with super micro-organisms that detoxify the leaves.

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