1. Saw-scaled viper (Echis carinatus)
When discussing venomous snakes, deadly could mean one of two things. It could either mean the snake that kills the most people, or it could mean the most highly toxic snake - the one that is most likely to kill you if it bites you.
These can be very different things, as those with the most potent venom are not necessarily the most common, commonly in contact with humans, aggressive, or bold.
The snake that is thought to kill the most people annually, and therefore the world's deadliest snake, is the saw-scaled viper, a particularly aggressive species found in the Middle East and central Asia. It is this aggression, as well as its presence in densely populated areas, that determines its deadliness, making it responsible for an estimated 5,000 human fatalities per year in India alone.