Undead Torch

You cause a corporeal undead to give off cold blue energy that disrupts the life force of living creatures but has no effect on objects, constructs, or undead. The target undead creature deals an additional 2d4 points of necrotic damage with its melee attacks. The attacked creature can take a WIS saving throw to negate the extra damage.

If the undead creature is destroyed, the Undead Torch continues to burn at the location of its destruction until the duration ends, and living creatures that come into contact with the remains take damage. If the undead creature assumes an incorporeal state (such as a vampire assuming Gaseous Form), the spell disperses harmlessly.