Arch Contaminator
Codex Supplement: Death Guard, p. 11
Such are this Warlord's virulent emanations that his very presence is enough to make even the most lethal toxins and venoms deadlier still.
This Warlord and any attached unit gain the Poison (4+) special rule on all equipped Melee weapons. If a weapon already has the Poison (x) special rule, improve the value of (x) by 1 to a max of 2+.