Bone Claws

Choose a creature you can see within range. You infuse them with osteomantic energy, growing sharp claws from their carpal bones. For the duration, the target’s unarmed attacks deal an extra 1d4 slashing damage on a hit.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases to 1d6 at 2nd level, 2d4 at 3rd level, 2d6 at 4th level, and 3d4 at 5th level.

From Steinhardt's Guide to the Eldritch Hunt.