Toxin Fog

You release a cloud of poisonous gas, obscuring your self and poisoning those around you. Creatures have disadvantage on attacks against you until the beginning of your next turn. Creatures in a 5ft radius around you must make a Constitution saving throw. Creatures takes 2d6 poison damage on a failed save, or half as much damage on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 and the size of the sphere increases by 5ft for each slot level above 2nd.