Death's grasp

You strike out against a creature within reach as your hand is wreathed in shadowy clouds. The target of this spell is grappled and must make a Constitution saving throw. On a failed save, the target takes 1d6 Necrotic damage. The escape DC for the grapple is your spell save DC. Each turn while grappled in this way, you may take a bonus action to automatically deal 1d6 Necrotic damage to the target.

Cantrip Upgrade. The damage increases by 1d6 when you reach levels 5 (2d6), 11 (3d6), and 17 (4d6).