Amalgamation Beast

Known also as Host of Souls, and Knots of the Damned, when mortal emotions reach the Realm of Chaos, they often take the form of individual Daemons. On occasion, though, they clump together to form unruly blobs of energy that function like cancers in the void. When they get too large, they are ejected into the Chaos Wastes where they take shape, becoming something out of a madman’s nightmares.

The Amalgamation Beast is a massive bag of undulating flesh. Its hide consists of countless faces stitched together and animated by Chaos. Each individual face is frozen in some expression of joy, hate, love, or despair, lending to its madness-inspiring appearance. It pulls itself along with great tentacles that shoot forth from its quivering body and drag it forward so that it can rend its foes with its gnashing teeth. And when it slays a mortal, the tentacles pull the corpse close so it can absorb the body, adding one more face to its form.

Source

 * Warhammer Fantasy RPG 2nd ED -- Tome of Corruption -- pg. 112