This is the Saola - a critically endangered species from the Vietnam/Laos area.
This species is so rare, that it is often referred to as the "Asian unicorn". Saola is related to cattle, with an appearance similar to antelope. They stand approximately 3ft tall, and weigh around 220lbs. Their two horns can reach up to 20 inches in length.
It is unknown how many Saola remain in the wild, due to how seldom they are seen. However, their populations have been severely diminished due to illegal hunting, due to a growing market for wild game in Asia for food and medicine. They are also threatened by habitat loss caused by deforestation.
To learn more about Saola, and find out what you can do to help, visit the WWF page: http://www.worldwildlife.org/species/saola
I am an archaeologist, Oregon Zoo Guide, and wildlife biology student. Much of my time is spent at the zoo with the bears, or out on the nature trails of the Columbia Gorge.