The smallest animal on earth is the tardigrade. The tardigrade is also known as the moss piglet or water bear.
Tardigrades are identified by their segmented bodies. These animals have eight legs. Tardigrades are described as looking like chubby and short caterpillars. They are found in a variety of locations around the globe, from the highest mountains to the deepest oceans.
Tardigrades are invertebrates. An invertebrate is an animal that lacks a backbone. Invertebrates represent a wide range of animal species from spiders to starfish to jellyfish. In fact, approximately 97 percent of all animals on the planet are invertebrates.