They can be distinguished from one another by the black tip on the end of a stoat's tail. It is the world’s smallest carnivore. Its length rarely exceeds 23 centimeters. The least weasel (Mustela nivalis), which measures 11–26 cm (4–10 inches) long and weighs only 25 grams (0.9 ounce), is the smallest. It has reddish-ginger fur, which … The largest is the sea otter (Enhydra lutris) at about 1 metre (3.3 feet) long and a weight of 25–45 kg (55–99 pounds). According to Blackfoot legend, this species is the bravest of all animals, a hunter that is bold out of proportion to its size. Interesting Facts Least Weasels are also known as: Weasel Stoats and Least Weasels look very alike. It hunts day and night, aided by its sharp nails and long slender body. The Least weasel lives deep in the Northeast Asian deciduous forest. The Least Weasel (Mustela nivalis) is the smallest living carnivore on the planet!