10. The Plague of Undeath – Warcraft III, World of Warcraft
In an effort to clear the path for the Burning Legion to invade, the Lich King Ner'zhul – acting under the instruction of one of the Burning Legion's demonic overlords Kil'jaeden – created a disease that would kill all who were afflicted by it, only to revive them in a new form that was neither living or dead – the Plague of Undeath. The purpose of this affliction was to forge the Scourge, essentially an army of undead warriors that would clear the way for the Burning Legion's eventual invasion of Azeroth.
Utilizing the services of Kel'Thuzad, a former mage of the Kirin Tor, Ner'zhul – as the Lich King – was able to disperse the plague within the very heart of the kingdom of Lordaeron, spreading it via infected grain to the populace. Victims afflicted by the plague would die within three days, returning to 'life' as mindless undead under the control of the Lich King.
An event for World of Warcraft revolving around the Plague of Undeath was created by the game's developers to promote the impending release of the Wrath of the Lich King expansion pack.
