Drop Anvil

You conjure an anvil that does 1d12 every 10ft it falls and the creature must make a DC 10 plus your spell casting modifier dexterity saving throw on failure the creature must make a DC 8 plus your spell casting modifier strength or be knocked prone. you can use your bonus action on sequential turns to drop it again. Every 10ft the anvil falls it takes 1d6 damage. Anvil HP: 60