Blight

Casting Time: 1 action.
Range: 30 ft.
Duration: Instantaneous.
Necromantic energy washes over a creature of
your choice that you can see within range,
draining moisture and vitality from it. The target
must make a Constitution saving throw. The
target takes 8d8 necrotic damage on a failed save,
or half as much damage on a successful one. This
spell has no effect on undead or constructs.
See PHB pg. 219.