World's Deadliest Snake

Cobras, vipers, and closely related species use venom to immobilize or kill their prey. The venom is modified saliva, delivered through fangs. The fangs of 'advanced' venomous snakes like viperids and elapids are hollow in order to inject venom more effectively, while the fangs of rear-fanged snakes such as the Boomslang merely have a groove on the posterior edge to channel venom into the wound. Snake venoms are often prey specific, its role in self-defense is secondary. Venom, like all salivary secretions, is a pre-digestant that initiates the breakdown of food into soluble compounds, facilitating proper digestion. Even "non-venomous" snake bites (like any animal bite) will cause tissue damage.
Certain birds, mammals, and other snakes such as kingsnakes that prey on venomous snakes have developed resistance and even immunity to certain venom. Venomous snakes include three families of snakes and do not constitute a formal classification group used in taxonomy. The term poisonous snake is mostly incorrect—poison is inhaled or ingested whereas venom is injected. There are, however, two exceptions—Rhabdophis sequesters toxins from the toads it eats then secretes them from nuchal glands to ward off predators, and a small population of garter snakes in Oregon retains enough toxin in their liver from the newts they eat to be effectively poisonous to local small predators such as crows and foxes.