Aeternae

The Aeternae are creatures who were thought to live in North India. They have a horn in the center of their heads with saw-like edges, which they attack with. These creatures supposedly were responsible for killing several soldiers in the army of Alexander the Great. Some have theorized they may be based off of the antelope.

Citations:

Bane, Theresa. Encyclopedia of Beasts and Monsters in Myth, Legend and Folklore. United States, McFarland, Incorporated, Publishers, 2016.