Hunters have been known to be the biggest and baddest of them all in the Halo series, the send fear down your spine when you see one, especially on Legendary mode. But the most ironic thing is there is a extremely easy way to kill them!
In Halo: CE a magnum can kill a hunter with 1 bullet! all you have to do is have him lung at you, dodge his attack, you will see his orange spine on his back, shoot it, dead.
If you load up The Silent Cartographer mission in Halo: CE get to the point in the video (with a magnum equipped) you can kill the Hunters, then reload the checkpoint and rinse and repeat until you reach the amount required for the achievement.
Video was done by Golden Cable Productions