Claws of the Umber Hulk

When this spell is cast, the subject's hands widen and his fingernails thicken and grow, becoming equivalent in size and power to the iron-like claws of an umber hulk. The transformation takes one full round and is excruciatingly painful, requiring a system shock roll. A failed roll causes the subject to suffer 3d4 points of damage.
The subject can burrow as an umber hulk, cutting through 10 feet of solid stone or 60 feet of soil per turn. The only limitation to this is the subject's stamina; at the end of each turn of burrowing, the subject must succeed a Constitution check or be forced to rest for one turn.
Burrowing through soil does not necessarily create a passable tunnel. If the subject wishes to make a passage in which others can travel or that he can exit when the spell ends, he must dig at a rate of 30 feet per turn. Cutting a tunnel through solid rock does not require extra care or time.
The recipient of this spell can make two claw attacks per round, each inflicting 2d6 points of damage plus any Strength bonuses. Each attack is made with a -2 penalty to hit. This penalty applies until the subject has made two successful consecutive attacks (not necessarily in the same round), at which time he is accustomed to using the claws. The penalty is dropped for the remainder of the spell.

[Tome of Magic]

School: Alteration
Level: 6
Rarity: Uncommon

Range: Touch
Components: V, S, M
Duration: 1 turn/ level
Casting Time: 1 round
Area of Effect: One creature
Saving Throw: None

Material Components:
an umber hulk's claw