Halys Pit Viper

The Halys pit viper is a stout venomous snake with a broad triangular head, vertical pupils and a heat-sensing pit between each eye and nostril. The grey, tan or reddish back carries dark crossbands or rounded blotches, while a dark stripe runs from the eye toward the jaw. Keeled scales give the body a rough texture. Its thick build and short tail contrast with racers, but colour varies and it should never be approached. (Wikipedia, Gloydius halys account)

This viper occupies rocky steppe, scrub, grassland and mountain slopes across much of Central and northern Asia, including Mongolia. It usually waits in ambush for small mammals, lizards and frogs, striking and tracking prey with venom. Activity shifts with temperature, and cold-season dormancy is necessary across the northern range. Females bear live young rather than laying eggs. The opened source did not identify a safe Mongolian observation site or local seasonal calendar; distant, undisturbed viewing is essential wherever encountered. (Wikipedia, Gloydius halys account)