Iron Maiden

could refer to one of four techniques:
*Black Secret Technique Machine One Shot, known in the English anime as Secret Black Move: Iron Maiden, used by Kankurō.
*Black Secret Technique Machine Two Shot, known in the English anime as Secret Black Move: Iron Maiden 2, also used by Kankurō.
*Black Passing Secret Fang Technique Machine One Shot, used by Kankurō and Kiba in unison. 
*Summoning: Iron Maiden, used by Ibiki.