Rot

You infuse a creature with a powerful burst of necrotic power, causing its flesh to blacken and fall away. The target must make a Constitution saving throw. On a failure, the target takes 9d8 necrotic damage and has disadvantage on attack rolls and ability checks until the end of your next turn. On a success, it takes half as much damage and suffers no other effects.

Constructs and undead automatically succeed on this saving throw, while plants have disadvantage.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th.