Relishing in their brutality and savagery, the World Eaters were among the first legions to betray the Emperor and join in service to the forces of Chaos. Cybernetically enhanced to bring out their vicious fighting abilities, the "Butcher's Nails" implants allow these Traitor Space Marines to become forces of nature unto themselves. Devolving into warbands from their united Legion, they nevertheless spread the bloody worship of their Chaos God Khorne through destruction and death.