Cole's Shadow Tentacles

Shadowy, grasping tentacles fill a 20-foot square on ground that you can see within range. The ground becomes difficult terrain for the duration of the spell.

When a 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 1d4 bludgeoning damage, 1d6 radiant damage and be Restrained by the tentacles until the spell ends. A creature that starts its turn in the area and is already Restrained by the tentacles takes 1d6 radiant damage.

A creature Restrained by the tentacles can use its action to make a Strength check against your spell save DC. On a success, it frees itself.

The damage of this spell increases by 1d6 radiant damage for each spell slot above 2nd level.