Vine minor

You target any hostile creature you can see within range of the spell, the creature must make a saving throw of (8 + proficiency bonus + wis modifier ) or it will be restrained and must make a saving throw at the beginning of its turn in order to break free. 

When a creature fails its saving throw, the next attack roll against that creature may add 1d4. Once the 1d4 has been rolled, you must fail your saving throw again before rolling it again. 

At 7th level it increases by 1d4 (2d4)