The smallest animal on earth is the tardigrade. The tardigrade is also known as the moss piglet or water bear. More »

Leaving aside invertebrates, which are often microscopic, the smallest land vertebrate is Paedophryne amauensis. This tiny frog was discovered in the jungles of New Guinea, and adults are only 0.27 inch long. More »

The blue whale is the largest mammal on earth. This species reaches lengths of 100 feet long and weighs up to 200 tons. The blue whale is believed to be the largest mammal ever to exist on earth. More »

The tardigrade (Hypsibius dujardini), also known as the water bear, is considered the toughest animal in the world. These micro-animals can survive in environments that would kill almost any other creature. More »

The strongest animal on Earth is the blue whale. The blue whale is also the largest creature in the entire world. More »

The animal that has the fewest neurons and is therefore a candidate for being the least intelligent is Caenorhabditis elegans, a nematode worm that lives in the soil. This nematode is the first animal to have its nervous... More »

There are two contenders for the world's smallest mammal, depending on whether one is going by length or weight. The world's lightest mammal is the Etruscan shrew, while the shortest is Kitti's hog-nosed bat. More »