Since "Man" doesn't count, I'd say man's greatest enemy is probably some species of virus. I wouldn't call "disease" a greatest enemy since that's like replacing the first "man" in the phrase "man is man's greatest enemy" with "vertebrates". It's not an enemy.
I suppose if you want to be really picky it has to be an individual, so I would suggest Kim Jong-Un as the individual who is likely to cause the most deaths, in terms of expected value.
I suppose if you want to be really picky it has to be an individual, so I would suggest Kim Jong-Un as the individual who is likely to cause the most deaths, in terms of expected value.
