The Sniper Spectre is a variant of BRD-01 Spectre employed by the IMC. They are exclusive to the Frontier Defense game mode. They have been replaced in Titanfall 2's Frontier Defense by regular Grunts wielding Charge Rifles. They also reappear as a similarly named Burn Card in Titanfall: Assault called Sniper Spectres.
The Sniper Spectre is identified by a flat black paint job with red trim, use of the Longbow-DMR Sniper & Charge Rifle for anti-Titan attacks, alongside the ability to cloak which - like the Tactical Ability available to Pilots - is very effective against Titan optics but much less so against Pilots, especially at close range. Sniper Spectres have quite a high degree of accuracy and seem especially adept at hitting moving targets, which when combined with their cloaking ability and propensity to quickly shift their firing positions can make them a nuisance to dispatch. However, their threat level versus the Harvester is relatively low due to their low damage output; they are, however, extremely effective at taking out placed Light Turrets.