At one point in the Spirit Temple in The Legend of Zelda: Ocarina of Time, Link must fight an Iron Knuckle that turns out to be a hypnotized Nabooru, who returns to her senses after being defeated. By clipping the camera through her Iron Knuckle armor, you can see her head modeled underneath her helmet, likely to facilitate the post-defeat cutscene where her armor falls off.

Furthermore, every other Iron Knuckle in the game also has a placeholder Gerudo head modeled underneath the helmet. While much of the head's face is obscured by chainmail, the details that are present indicate that it is most likely an early version of Nabooru's design; of note is that the head's hairstyle is closer to that seen on Gerudo Village's guards, implying that this element was reused for them when Nabooru's design was revised to the version seen in the final game.

This placeholder head is also present inside the Iron Knuckles that Link encounters in The Legend of Zelda: Majora's Mask, due to that game reusing many assets from Ocarina of Time.