5. Saw-scaled viper

The saw-scaled viper (Echis carinatus) is the smallest member of the "Big Four" in India — along with Russell's viper, the common krait (Bungarus caeruleus) and the Indian cobra (Naja naja) — thought to be responsible for the most bites and related deaths in the country. Along with their fellow vipers, the Russel's viper and the pit viper, these nondescript little reptiles may be responsible for about 58,000 deaths a year in India alone.