There is no snake that can outrun a man,unless yor foolish enough to get cornered,most of the deaths involving snakes r becuz idiots r trying to kill it(I met one guy who shot a diamondback,well the bullet hit the back of the snakes head,which launched the snakes head towards the man,and the decapitated head bit him on the leg mid flight). Also water moccasins do mock charges,they rarely bite unless stepped on. In a study with 22 water moccasins only one could be made to bite,and only when the glove was stuck in its mouth.