Venomous Vine

You summon a writhing thorny tendril of a highly venomous plant which you wield as a whip.  You may use an action on subsequent turns to make a ranged spell attack against a target within 15 feet that deals 1d6 + your Proficiency Bonus Poison damage. You may also use this whip to grapple a creature within 5 feet as an action, with the creature making an Acrobatics (Dexterity) or an Athletics (Strength) check against your Spell Save DC and taking 1d6 + your Proficiency Bonus Poison damage each turn spent grappled. You may not move more than 5 feet away from the grappled creature and must use your bonus action every turn to maintain the grapple. A creature grappled in this way may make an additional check to escape the grapple at the start of each of it's turns. Losing concentration on the spell ends the grapple.

The spell's damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).