Thorns

Magical thorns with steel tips begin to encircle target for the duration. You can end the spell early by using an action to dismiss it.  Whenever a creature within 5 feet of you hits you with a melee attack, the thorns lash out damaging the attacker.  The attacker takes 2d8 piercing.

** If a bit of poison is used during the casting, the thorns become poisonous.  The attacker takes additional 2d6 poison damage and must succeed on a Constitution saving throw or be poisoned.  The attacker can attempt to save at the end of each of its turn.  

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher the damage (thorns only) increase by addition 1d8 for each slot above 3rd.