Naerr Coolkoord was a Human male Mandalorian warrior and bounty hunter that lived during the twilight reign of the New Republic. A professional member of the Bounty Hunters' Guild that was active throughout the course of the First Order-Resistance War and the period of heightened geopolitical tensions that preceded the onset of open hostilities, during this time, Coolkoord was frequently hired by the First Order and its proxies to hunt and capture defectors, traitors, spies and known members of the Resistance, his long-standing ties with the secretive military junta stretching back to precede its emergence and official formation in 29 ABY, prior to which Naerr was affiliated with the Amaxine warriors, a paramilitary organization that employed the Mandalorian mercenary for his services as a hired blaster during their attempts to destabilize the New Republic. In addition, Naerr also possessed connections to the Ortiz crime family, an Urgunian syndicate that shared his affiliation with the First Order. Although their military forces created the official face of the neo-Imperial regime, Naerr Coolkoord and various other elements that worked as frontmen were crucial to helping spread its influence on a wider scale. Because of these allegiances, Coolkoord was considered a "clanless one" by Mandalorians that harbored a stance that opposed those of his clientele.
At some point following the Hosnian Cataclysm, Coolkoord engaged in a dogfight with the Spectre, a modified Barloz-class freighter belonging to the Bokken Jedi Ezra Bridger, his partner Sabine Wren and Isis Bridger, his twin sister, in an attempt to collect the significant bounty placed on their heads due to their links to the Resistance. The crew of the Spectre, however, was able to successfully escape after inflicting considerable damage to his M3-A Scyk fighter. Throughout his career, Naerr Coolkoord wore a suit of white Mandalorian armor that was slightly reminiscent to that utilized by the Imperial Super Commandos of the Galactic Empire in terms of both coloration and design, which was a common style among those mercenaries of Mandalorian heritage that gave their allegiance to the First Order, a successor of the Imperial war machine.