Witch Bolt

Action | 60 ft | V/S/M | Concentration, 1 min

Make a ranged spell attack against it. On a hit,
the target takes 2d12 Lightning damage.
On each of your subsequent turns, you can take a
Bonus Action to deal 1d12 Lightning damage to the
target automatically, even if the first attack missed.
The spell ends if the target is ever outside the spell's
range or if it has Total Cover from you.

Higher-Level Slot.
Initial damage add 1d12 per slot level above 1.