Corrosive Cleave

You brandish the weapon used in the spell’s casting, causing it to be coated in a black, corrosive liquid. Make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects, and if your current hit points are more than half of your maximum hit points, the creature takes an extra 1d6 acid damage.

At Higher Levels. At 5th level, the melee attack deals an extra 1d6 acid damage to the target on a hit, and the acid damage the target takes increases to 2d6. Both damage rolls increase by 1d6 at 11th level (2d6 and 3d6) and again at 17th level (3d6 and 4d6).