Whip of the Deep

As a Bonus Action you can conjure from somewhere on your body two long black tentacle that can whip out to two targets or the same one if you choose.  The target takes 1d6 bludgeoning damage and 1d4 poison damage and must succeed a Dexterity saving throw against your spell DC or be grappled.  At the beginning of their turn, they can make a Dex or Strength save as an action to escape the grapple.  As a Bonus Action, you can move this tentacle and take a grappled target with you.  Any attack you make against a creature grappled in this way has advantage.