According to Human history including mythology, which being killed more Humans in one single attack than any other ?

I think I have the answer unless you can think of one who killed more people.
According to certain books connected to the Abrahamic religions a God called Yahweh/Allah/Jah caused a flood in about 2300BC with the sole purpose of killing Humans.
Also, according to biblical scholars the Human population would have been at least and probably far more than 750 million people....
Has anything else ever racked up such a massive kill score with one attack ?