There are approximately 2,700 species of snakes worldwide, of which around 300 are venomous. Snakes range in habitat from deserts to forests to oceans. The most deadly snakes are the Black Mamba, Common Krait, Russell's Viper, Taipan, and Indian Cobra. These snakes have potent neurotoxins or cardiotoxins in their venom that can prove fatal if not treated.