Talons of Night

Multiple clawed draconic hands sprout out of the ground in a 20-foot-radius sphere at a point you can see within range and begin ripping apart the ground, tearing chunks of earth up and causing unstable footing. When a creature starts its turn there and each time a creature enters the spells space for the first time, they must make a strength saving throw (Huge and larger creatures have advantage on this save) or take 5d10 bludgeoning damage and be knocked prone on a failed save. On a success a creature takes half as much damage and is not knocked prone.

Additionally, the area of the spell becomes difficult terrain. 

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d10 for each slot level above 6th.