Whip Of Death

You create a black glowing whip and swing the whip at the target. The target is grappled in the grasp of the whip. At the start of their turn, for 3 turns, unless they succeed on a dexterity saving throw, they take 4d8 necrotic damage.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 1st.