Defending Bone

Necromancy
Level: Artificer * 2, Cleric */Oracle * 2, Inquisitor * 2, Magus * 2, Sorcerer */Wizard * 2, Warlock * 2
Components: V, S, F (a Medium creature's skull or femur), DF
Casting Time: 1 Standard Action
Range: personal
Target: you
Duration: 1 hour/level or until discharged
Saving Throw: -
Spell Resistance: -
  You animate a bone with necromantic energy, giving it the power to float near your body and interpose itself against physical attacks. This gives you Damage Reduction 5/bludgeoning.
  Once the bone has prevented a total of 5 points of damage per Caster Level (maximum 50 points), it is destroyed and the spell is discharged. This spell has no effect if you have Damage Reduction from another source.