Toxic Shield

You gain resistance to poison damage and advantage on saves against being poisoned for the duration. In addition, whenever a creature within 5 feet of you hits you with a melee attack, the shield sprays them with poison, dealing 1d8 poison damage to the attacker.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the poison damage increases by 1d8 for every 2 slot levels above 1st.