Crown of Thorns

You create a crown made of thorns on the target's head. The target must roll a wisdom saving throw, on a failed save it takes 2d6 piercing damage and is bound to the crown for the duration of the spell. At the beginning of the creature's turn, it may try to undo the crown, rolling a wisdom saving throw. On a failed save it takes an additional 1d6 piercing damage. On a save, the crown crumbles and falls off.

At Higher Levels:
Starting at 3rd Level, all of the spell's damage output increases with 1d6.