Wind Up Mechanism

You target a non-magical, Medium or smaller object that isn't being worn or carried. You manifest a spectral wind-up key in the object and "crank" it, imbuing it with a repetitive, violent kinetic motion of your choice (such as slamming, spinning, or hopping).

The object occupies its space and is treated as a hazard. Any creature that starts its turn within 5 feet of the object, or enters that area for the first time on a turn, must succeed on a Strength Saving Throw. On a failure, the creature takes 2d8 Bludgeoning damage and is pushed 10 feet away. On a success they take half damage and are not pushed. 

As a Bonus Action, you can command the object to "march," moving it up to 20 feet to an unoccupied space you can see.