Who was the greatest assassin ever known? Or rumored to exist?

Question

Forget someone like Lee Harvey Oswald or John Wilkes Booth. They were both one hit wonders. I'm talking about someone who reigned the criminal world as an assassin, one hit after another.

Answer 1

There have been numerous assassin that have been considered great... But some of the greatest assassin that have every lived were your Ninjas and a couple of Chinese assassin...... But before I go into their job record I need to know is that what you are looking for....................

Answer 2

chupacabra!

Answer 3

Gotta say Carlos the Jackal. He was dangerous, feared, and even inspired a whole bunch of fictional assassins like him, from DAY OF THE JACKAL to THE BOURNE IDENTITY (novel).  

Answer 4

Chupacabra

Answer 5

Alteir!