The Collaborative International Dictionary
marco polo sheep
marco polo sheep \marco polo sheep\, marco polo's sheep \marco polo's sheep\n. An Asiatic wild sheep ( Ovis poli) with exceptionally large horns; sometimes considered a variety of the argali: Ovis ammon poli.
Wikipedia
Marco Polo sheep
The Marco Polo sheep (Ovis ammon polii) is a subspecies of argali sheep, named after Marco Polo. Their habitat is the mountainous regions of Central Asia. Marco Polo sheep are distinguishable mostly by their large size and spiraling horns. Their conservation status is " near threatened" and efforts have been made to protect their numbers and keep them from commercial hunting. It has also been suggested that crossing them with domestic sheep could have agricultural benefits.