Melee infantry unit.
It was the gruesome experiments of Angron, Primarch of the World Eaters, that led to the creation of the first Berzerkers. By the ritual lobotomisation of his warriors, he removed all sense of fear and danger and then heightened the rush his soldiers experienced in combat. When the Legion swore itself to Khorne, the Berzerkers were no longer bound by Imperial battle doctrine and were given full rein to exercise their bloodthirsty skills. They have since become the ultimate close combat shock troops, entering an uncontrollable frenzy in the heat of battle.