Acid Tendril

A tendril of acid forms around your arm that you then whip out in front of you in an arc. Each creature in a 15-foot cone must make a Dexterity saving throw. A creature takes 3d6 acid damage on a failed save, or half as much damage on a successful one.

The acid sticks to anything that fails its saving throw and does half of rolled damage per player turn until the affected creature uses an action to wipe it off. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for each slot level above 1st.