Pyramid Head is one of those villains that you're not supposed to think about too much. He's a fan favorite, and an important aspect of the world of Silent Hill. Voiceless. Faceless. Emotionless. Malevolent. Unkillable. He's more a force than a character.
He's wearing an iron hat that contains enough metal to build an SUV, which covers his eyes. It's a miracle he can cross the room without tripping over things, let alone eviscerate people with his surfboard-sized sword. He can barely drag the thing, much less wave it around in combat. It seems like the only thing you would need to escape the clutches of Pyramid Head would be the gift of walking.
He's in Silent Hill Homecoming, although it looks to me like he's just not into it anymore. I think the celebrity lifestyle is getting to him.
Shamus Young is a programmer and writer by trade, videogame nitpicker by inclination. If you have the patience for more of his ramblings, they can be found at ShamusYoung.com.