Look who is making his Dawn of War debut in the new expansion, Chaos Rising:
http://www.thq.com/relic_holiday/index.html
The Great Unclean One
Walking mountains of rotting flesh. Jovial grandfathers of the legions of Nurgle. Repulsive and gregarious in equal measure.
The Great Unclean Ones are the mightiest daemons of Nurgle, the Chaos God of Plagues and Death, and they are perfect avatars of the Lord of Decay's own dichotomies.
Horror Made Flesh
In terms of physical presence, these mighty daemons are utterly revolting. Manifest on the physical plane, they inhabit tons of necrotic flesh. They tower over the battlefield, shambling and oozing forward on stout legs that seem unable to support their massive girth.
This fleshy mountain contains all the rot and pestilence that is Nurlge's to command. Gaping, gangrenous wounds expose organs writhing with maggots. Colonies of flies buzz within the terrible miasma that rises from the daemon's body. Smaller daemons called Nurglings crawl between the great folds of flesh, suckling on weeping sores and cankers. Powerful arms wield daemon blades dripping with poisonous death.
And atop it all sits a wide, leering head. Cracked horns rise among welts; eyes ablaze with vile intelligence leer from behind seeping wounds; an impossibly long tongue lolls out and licks the ichor from the daemon's own flesh.
The Charms of the Grave
The daemon's personality seems at complete odds with its nightmarish form. Instead of the inchoate rage or cackling sadism one might expect, the Great Unclean One chuckles with the deep laugh of a benevolent grandfather.
Like the Dark God he serves, the Great Unclean One is genuinely affectionate toward the legions of daemons and heretics he commands. After all, they have seen the truth of Nurgle and have received his gifts.
The Great Unclean One can even be charming toward those who oppose him. With a redolent laugh, the daemon may thank an enemy who has killed some of his agents -- for in delivering death to them, the enemy too does Nurgle's work.
The daemon's gregarious nature quickly falls away, however, when an enemy genuinely impedes Nurgle's grand plans. Then, an apocalyptic rage wells up in an unstoppable torrent and whole worlds can shatter with the Great Unclean One's fury.
The Weapons of Decay
Sitting at the apex of Nurgle's hordes, the Great Unclean One wields tremendous power. His physical form, though riven with rot and decay, is extremely powerful, allowing it to smash and rend any enemy foolish enough to come near.
The daemon may also expel some of the endless reserves of bile and toxin that roil within its endless bowels. From raising plagues of flies, to toxic clouds of poisonous gas, to great fonts of acidic vomit, the daemon is always happy to share Nurgle's gifts with its enemies.
The most honored enemies may even be privileged enough to see the full might of the daemon's flesh -- as they are drawn in through its gaping orifices and are utterly consumed.