Curse of the Deep

You place a curse on a creature that you can see within range, fillings the creature's mouth with saltwater. Until the spell ends, you deal an extra 1d6 cold damage to the target whenever you hit it with an attack. When you damage a creature that is concentrating on a spell, that creature has disadvantage on the saving throw it makes to maintain its concentration. If the targets drops concentration, the next attack roll made against this target before the end of your next turn has advantage.

If the target drops to 0 hit points before this spell ends, you can use a bonus action on a subsequent turn of yours to curse a new creature.

A Remove Curse cast on the target ends this spell early.