Whirlwind

Monster Manual - 5e, D&D Basic Rules

Whirlwind (Recharge 4–6 ). Each creature in the elemental’s space must make a DC 13 Strength saving throw. On a failure, a target takes 15 ( 3d8 + 2 ) bludgeoning damage and is flung up 20 feet away from the elemental in a random direction and knocked prone. If a thrown target strikes an object, such as a wall or floor, the target takes 3 ( 1d6 ) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 13 Dexterity saving throw or take the same damage and be knocked prone.