Horned pit viper, Fan-si-pan horned pitviper
Protobothrops cornutus, commonly known as the horned pit viper or Fan-Si-Pan horned pitviper, is a venomous pit viper species found in northern and central Vietnam and in southern China (Guangdong). No subspecies are currently recognized.
The type locality given is "Fan-si-pan mountains, Tonkin, Indo-China" (=Mount Fansipan). It is currently known from several provinces in Vietnam (Lao Cai Province, Ha Giang Province, Quang Binh Province, Thua Thien-Hue Province, Lang Son Province). The only Chinese record is from Ruyuan Yao Autonomous County in northern Guangdong and was originally described as a new species, Ceratrimeresurus shenlii.
It occurs in evergreen forest on both karst and granitic outcrops at elevations of 250–2,000 m (820–6,560 ft) above sea level.