Eldritch Cannon

You create a spectral, eldritch cannon within range that lasts for the duration or until you cast this spell again. When you cast the spell, you can make a ranged spell attack against a creature within 60 feet of the weapon. On a hit, the target takes force damage equal to 4d8 + your spellcasting ability modifier.

As a bonus action on your turn, you can move the weapon up to 20 feet.

The cannon can take whatever form you choose.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for every two slot levels above 3rd.