The Rarest Mammal On The Planet Was Spotted In Vietnam

© William Robichaud/WWF

One of the rarest animals in the world, a wild saola, has been photographed alive in Vietnam for the first time in 15 years, according to a statement from the World Wildlife Fund (WWF).

The saola looks like an antelope. It's characterized by two parallel horns that can measure up to 20 inches long.

The animal is so rare that is has been dubbed the "Asian Unicorn."

"When our team first looked at the photos we couldn't believe our eyes," Dr. Van Ngoc Thinh, WWF-Vietnam's Country Director, said in a statement. "Saola are the holy grail for South-east Asian conservationists so there was a lot of excitement."

The saola was first discovered in 1992 in Vietnam near its border with Laos when a survey team from the WWF and Vietnam's forest agency found a skull with unusual horns in a hunter's home. This was the first new large mammal discovered in more than 50 years, according to the WWF.

WWFA camera trap photo taken on Sept. 7, 2013, in the early evening shows a single saola moving along a rocky forest valley stream in a remote corner of the Central Annamite mountains of Vietnam.

In 2010, villagers in Laos captured a saola, but it died after several days in captivity. That was the first confirmed record of the species since 1999 when two photographs were taken of a wild saola in Laos.

Since the saola is hardly ever seen, very little known is about its behavior or even how many are out in the wild. Experts believe that no more than a few hundred exist.

The saola is listed as critically endangered on the IUCN Red List. The animal faces threats from hunting - they may be caught in snares to catch animals like deer for the illegal wildlife trade - and loss of habitat from road construction.

The most recent saola sighting gives conservationists a better idea of their range and will help with protection efforts.

Here's a video of the elusive saola: