Business Insider recently made a list of some of the smallest animals on Earth. The first on their list is the pygmy rabbit. They are native to West Coast of the United States and can be as small as 9.25 inches long. Pygmy Marmosetsare are 4.6 inches longand wrap their entire body around a human finger. Finally, the Barbados Threadsnake is the smallest snake in the world and can be measured at 4.1 inches long.