Caustic Spray

You let loose a quick spray of a caustic chemical fog. Creatures within the fog take 1d4 + your Proficiency Bonus Acid damage and must make a Constitution Saving throw. Creatures who fail the save take an additional 1d4 + your proficiency modifier at the start of your next turn.

This spell's secondary damage increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).