The Marco Polo sheep, scientifically known as Ovis ammon polii, is a species of wild sheep native to Central Asia. It is also known as the Pamir argali or the Tajik argali. The name "Marco Polo sheep" was given to it due to the famous explorer's description of the species during his travels through the region in the 13th century. Other synonyms for Marco Polo sheep include the Himalayan argali, Altai argali, and Siberian argali. These massive herbivores reside in extreme altitudes and have impressive horns that can grow up to six feet long, making them a popular trophy for hunters. Unfortunately, the species is threatened by illegal hunting and habitat destruction.