Clockwork Coffin

A set of spectral gears appear in any space within range. If cast in the space of a large or smaller creature it must succeed on a dexterity saving throw against your spell save (DC) or be restrained and held in an X-Position. Additionally, a target can be pulled into the coffin if it is grappled and no other creature is inside. When you cast this spell and at the start of each turn after the target suffers 3d6 bludgeoning damage. At the end of the creature's turn, it can make a Strength saving throw to escape the coffin.

At Higher Levels. When you cast this spell using a spell slot of 5th or higher level, the damage increases by 1d6, and can now target huge creatures.