Ensnaring Blow

You brandish the weapon used in the spell's casting and make a melee attack with it against one creature within 5 feet of you. On a hit, in addition to the melee weapon's normal effects, the target is hindered by thin sticky vines, reducing it's movement speed by 10ft until the start of your next turn.

At Higher Levels. At 5th level, the vines start to excrete an acid, making the melee attack deal an extra 1d8 acid damage to the target on a hit. This damage increases by another 1d8 at 11th level (for a total of 2d8 acid damage) and by another 1d8 at 17th level (for a total of 3d8 acid damage).