The Brown-throated three-toed Sloth is mostly brown or gray with bristly hair throughout its body. It has a rounded head and nose and shows no external ears or tail. The face is whitish or off-white with brown stripes running through the eyes. Its strange facial configuration makes it appear as if it is smiling. The Three-Toed Sloth often has beetles, mites and even algae growing on it. The algae gives the sloth a greenish appearance, useful in hiding from predators in the forest canopy. Male sloths have a bright yellow spot on their backs. Adults grow to a maximum weight of seven to ten pounds. Unlike most mammals, the three-toed sloth cannot maintain its own body temperature (similar to a reptile) and can only live in tropical locales.
Three-toed Sloths spend nearly all of their lives high in the rainforest canopy. They only descend to the ground to defecate. On land, the sloth is extremely clumsy as its long claws and weak hind legs force it crawl on its belly. Surprisingly, these animals are excellent swimmers. Sloths have extremely low metabolism and are among the slowest animals on Earth. In fact, Sloths spend 19 hours a day hanging upside down from branches sleeping.