Headhunter, who can also use Nth Metal weapons to his advantage was an unnamed warrior-shaman from a South American jungle tribe. He threatened St. Roch for decades (Cutting off and shrinking heads.)
He seems to have developed a particular fascination with Hawkman, to the point of gathering bones from the corpses of his incarnation and reviving them with the aid of some "Nth Metal dust," presumably collected from the various Hawkman-incarnate tombs, his weapons may also be created via Nth metal.
The first battle between them left Carter in such an angered state, he ended up meting out justice more brutally than usual for awhile.
Headhunter is a skilled mercenary who was opposed by several criminals. He ussually shoots twice. The second shoot is his trademark since he never misses the first shot to the head. This changed when he was hired to kill Commissioner Gordon and missed not once but twice, forcing him to spent a third bullet, the first in his career. He is stopped by Batman and taken into custody by Commissioner Gordon.