Chill Touch

Make a ranged spell attack against a creature.
The target takes 1d8 necrotic damage, and it can't
regain hit points until the start of your next turn. If you hit an undead target, it also has disadvantage on
attack rolls against you until the end of your next
turn.
This spell's damage increases by 1d8 when you
reach 5th level (2d8), 11th level (3d8), and 17th
level (4d8).