World's Deadliest Snake

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.
Snake venoms are complex mixtures of proteins and are stored in poison glands at the back of the head. In all venomous snakes these glands open through ducts into grooved or hollow teeth in the upper jaw. These proteins can potentially be a mix of neurotoxins (which attack the nervous system), hemotoxins (which attack the circulatory system), cytotoxins, bungarotoxins and many other toxins that affect the body in different ways. Almost all snake venom contains hyaluronidase, an enzyme that ensures rapid diffusion of the venom.