As the spell takes effect, the target's body screeches as its flesh darkens to polished black iron.

Daily   ✦     Arcane, Polymorph
Minor Action      Melee 1

Target: You or one ally

Effect: The target assumes the form of living iron. The form lasts until the target is affected by another polymorph effect, until you take a minor action to dismiss it, or until the end of the encounter. While in this form, the target gains vulnerable 20 lightning and is slowed. In addition, the target gains the following benefits.
✦     Resist 10 to all damage.
✦     Immunity to blindness, deafness, disease, and poison.
✦     No need to breathe, and thus cannot suffocate.
✦     +6 power bonus to melee damage rolls.

Published in Heroes of the Elemental Chaos, page(s) 117.