Koalas are slow-moving animals that sleep up to 22 hours a day. When they are awake they spend their waking hours munching on eucalyptus leaves. Koalas aren’t bears as many people are led to believe. Rather, they are members of the pouched marsupial family, which includes kangaroos and wombats. Found only in Australia, koalas are threatened by habitat destruction, bush fires and road accidents.
Sloths come in at a close second with 20 hours. Native to Central and South America, the tree sloth is also the slowest mammal, reaching a maximum speed of 1.5m (5 feet) per minute when on the ground. Of the six living species, only one, the maned three-toes sloth, is classified as “endangered”. Destruction of South America's forests, however, may soon prove a threat to other sloth species.
Then we have the complete opposite end of the spectrum coming in for 3rd place... Ever watchful for predators, the giraffe hardly ever sleeps. Averaging just 2 hours a day, this tall and elegant creature can usually last on just a few 5-minute naps each day. Too tall to lie down, they sleep standing up, resting their heads on their hindquarters.