Brown sloth hanging from mossy tree branch in tropical forest

If you're moving slow today, that's just fine: You're outpacing our rainforest-dwelling photo subject, which spends 90% of its time scarcely moving a muscle. Sloths (this one's a three-toed sloth—count 'em) move very little to conserve the scant energy gained from their leaves-only diet. They live most of their lives hanging from their hooked claws in trees like this cecropia, whose leaves are a favorite sloth food. Sloths even sleep in a dangling position, and they often snooze away 20 hours of the day. Jealous?