A nuckelavee's breath weapon is a cone of withering foulness that causes painful welts, cramps, and bleeding, and only harms living creatures-this damage bypasses all energy resistance and damage reduction. Non-creature plants in the area are affected as if by a blight spell. Any creature that fails its Reflex save against the breath weapon must make a DC 21 Fortitude save or contract mortasheen (see below). The save DC is Constitution-based.