Contagion Cloud

You create a large cloud of poisonous gas at a point within range that spreads out into a 20 ft. radius. Creatures in the spell's radius must make a Constitution Saving throw, taking 4d6 poison damage and becoming poisoned for 1 minute, or taking half damage and suffering no other effects on a success. A target poisoned by this spell can repeat the saving throw at the end of their turns, ending the effect on themselves with a successful save.

At higher levels. The damage increases by 1d6 per level above 3rd.