The only snake from the Americas on the list, the Rattlesnake is easily identifiable by the tell tale rattle on the end of its tail.
They are actually a part of the Pit Viper family, and are capable of striking at up to 2/3rd their body length.
The Eastern Diamondback in considered the most venomous species in North America. Surprisingly, juveniles are considered more dangerous than adults, due to their inability to control the amount of venom injected.
Most species of rattlesnakes have hemotoxic venom, destroying tissue, degenerating organs and causing coagulopathy (disrupted blood clotting).
Some degree of permanent scarring is very likely in the event of a venomous bite, even with prompt, effective treatment, and can lead to the loss of a limb or death. Difficulty breathing, paralysis, drooling and massive hemorrhaging are also common symptoms.
Thus, a rattlesnake bite is always a potentially fatal injury. Untreated rattlesnake bites, especially from larger species, are very often fatal.
However, antivenin, when applied in time, reduces the death rate to less than 4%