The Russell's Viper, Daboia russelii, is one of two Old World vipers in Sri Lanka. It causes the highest snakebite mortality in the country. Often encountered in dry brush, piles of debris, and under rocks where it hides during the day, this species is nocturnal but highly alert in the daytime. It is found throughout Sri Lanka, but is most common in the Dry Zone.

It is a prolific breeder. Clutches of up to 50 neonates have been recorded. They are ovoviviparous (the embryos develop inside eggs that are retained within the female's body until they are ready to hatch). The average length of the Russell's Viper is 1 to 1.5m. When threatened, they
emit a loud hissing sound similar to a steaming kettle and lunge at the perceived assailant.

As with the other venomous species in Sri Lanka, more research needs to be conducted to develop an effective antivenom against the Russell's Viper. The isolated population of this snake in Sri Lanka has haemotoxic as well as neurotoxic properties to their venom, unlike populations on mainland Asia.