Death Touch

You touch one creature. Make a melee spell attack against the target. On a hit the target takes 1d8 necrotic damage and their movement speed is halved until the end of your next round. If the target is missing any of their hit points, they instead take 1d12 necrotic damage.

The spell’s damage increases by one die when you reach 5th level (2d8 or 2d12), 11th level (3d8 or 3d12), and 17th level (4d8 or 4d12).