Pygmy three-toed sloths identified by their messy hairstyles and friendly faces might make you want to join the branch party, but these animals are not at all easy to find. Also known as the monk sloth or dwarf sloth, the species is endemic exclusively to a small island off the Caribbean coast of Panama, Isla Escudo de Veraguas. This species is significantly smaller than other kinds of sloths. They are about 50 centimetres in length and weigh between 2.5 to 3.5 kilograms. Sadly, the pygmy three-toed sloth is classified as critically endangered on the International Union for Conservation of Nature"s list.