Sleepiest marsupial

The world’s sleepiest species of marsupial is the koala (Phascolarctos cinereus). Because it has a very low-quality diet, subsisting almost exclusively upon the leaves of eucalyptus (gum) trees, it spends up to 18 hours out of every 24 asleep, in order to conserve energy. A koala typically eats no more than 600-800 g (21-28 oz) of leaves per day, which is equivalent to a human living on a single bowl of cereal per day.