Tartek the Enraged. One of the most powerful abominations the Scourge has ever created. Assembled by lich Amnennar the Coldbringer to assist in setting up a base at Razorfen Downs. Tartek single-handedly felled more than 1200 quilboar before finally being overcome. His sacrifice provided the corpses for Amnennar to quickly raise an undead quilboar army of his own, ultimately assembling the first major Scourge outpost on Kalimdor. Some of Tartek's remains were reanimated and used to create Glutton, Amnennar's current lieutenant.
Obrahiim, the Traveler. Brilliant architect, pivotal in the conception of Naxxramas, and mastermind behind the creation of Acherus. Quickly rose up the ranks from lowly skeletal peon to one of Kel'Thuzad's most trusted advisors.
Always the scholar, Obrahiim traveled the world in search of knowledge, notably taking most of his early inspiration from the architecture of the Nerubians and the magic of the orc warlocks. He was last seen several years ago, headed west to study the Ruins of Zin-Azshari in Kalimdor.
Diodor the Damned. Human necromancer, one of the first members of the Cult of the Damned, and decorated hero of the First War. Successfully led a contingent of Scourge to victory during the First and Second Summertide Assaults upon Scarlet Monastery. Killed in action during the Third (and final) Summertide Assault, which was successfully repelled by Scarlet Crusade operatives that had finally figured out his modus operandi.
Kirkessen the Zealous. Powerful lich who reported directly to the Lich King himself. A decorated veteran of countless battles, Kirkessen designed and led the Siege of the Sanguine, one of the largest organized assaults on Light's Hope Chapel. Despite overwhelming odds, his attack was quickly countered, and his forces suffered enormous damages. Kirkessen himself received a critical blow from Lord Maxwell Tyrosus, and is no longer able to assume a corporeal form.