What is the least venomous snake on earth?

The Eastern Massasauga

Is the least venomous of rattlesnakes. Not normally fatal to adults but can be fatal to children, pets and the elderly. Though if an adult gets bitten they would experience allot of the normal symptoms including swelling necrosis vomiting exc,exc. Just because it is the least venomous and not fatal does not mean that it is not harmful. It can leave detrimental problems if untreated.