Dragonice

You roar, transforming your head into a dragon's and unleashing icy breath. Each creature in a 30-foot cone must make a Constitution saving throw. On a failed save, a target takes 3d6 cold damage and is slowed until the end of its next turn.
The ice spreads around corners and freezes water in the area.
At Higher Levels.
When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.