Burrow

You touch a willing creature, whose hands sprout claws as hard as stone. For the duration, the creature has a burrow speed of 10 feet, but can't burrow through solid rock. Additionally, their unarmed strikes deals slashing damage equal to 1d6 + their Strength modifier. If the target's unarmed strikes deal more damage, they remain unchanged.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the target's burrow speed increases by 5 feet for each slot level above 2nd. The target can't burrow faster than its normal walking speed.