Few people have the opportunity to meet near-mythical beasts in real life — but Rob Timmins has. He’s one of the few biologists ever to spend time with a saola, a wild ox once known as the “Asian unicorn,” and arguably the most threatened large mammal on the planet.

The species is considered so evolutionarily distinct it’s placed in a genus of its own. Sporting a hefty pair of dark horns, a sloping back and bold flashes of white across the face, saolas resemble antelopes, yet their closest living relatives are wild cattle like gaur and buffalo.

Yet the world is on the cusp of losing this gentle, one-of-a-kind mammal forever, before scientists have even begun to unravel its mysteries.