Iron Bones

(Spell Compendium, page 125, DnD 3.5)

Transmutation

Level: ; Cleric 4; Sorcerer/Wizard 4
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Corporeal undead creature touched
Duration: 10 minutes/level
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)

A brief flash engulfs your undead ally, and through its flesh you can see its skeleton. The skeleton glows a dusky red for a moment.

This spell functions like stone bones (Spell Compendium page 208), except that the subject creature's skeleton changes to iron. The creature gains a +6 natural armor bonus to AC.

Arcane Focus: A miniature skull made out of iron or steel.