Waxing Tentacles

Squirming, aspen tentacles fill a 20-foot cube in an area that you can see within range. For the duration, these wax tentacles turn the ground in the area into difficult terrain.
When a hostile creature enters the affected area for the first time on a turn or starts its turn there, the creature must succeed on a Strength saving throw or take 1d6 bludgeoning damage and 2d6 fire damage and be restrained by the tentacles until the spell ends. A hostile creature that starts its turn in the area and is already restrained by the wax takes 1d6 bludgeoning damage and 2d6 fire damage. When a friendly creature enters the effected area for the first time on a turn or starts its turn there, the creature regains hit points equal to 2d6 + your spellcasting modifier. A friendly creature that starts its turn in the area regains hit points equal to 2d6 + your spellcasting modifier. 
A creature restrained by the tentacles can use its action to make a Strength or Dexterity check (its choice) against your spell save DC. On a success, it frees itself.