Unkindness of Ravens

A cloud of starving ravens fills a 20-foot cube you can see within range. For the duration, these ravens turn the area into difficult terrain.

When a creature enters the affected area for the first time on a turn or starts its turn there, the creature must succeed on a Dexterity saving throw or take 3d6 slashing damage and be restrained by the beaks and talons of the ravens until the spell ends. A creature that starts its turn in the area and is already restrained by the ravens takes 3d6 slashing damage.

A creature restrained by the ravens can use its action to make a Strength or Dexterity check (its choice) against your spell save DC. On a success, it frees itself.