Pyramid Head turns 20 years old this month, but time has not dulled the edge of its rusty blade one bit. There are a lot of reasons why Silent Hill 2 is still the best horror game ever made. It could be the haunting atmosphere, gruesome monster designs, Akira Yamaoka's peerless soundtrack, or the masterful subtlety and psychological depth of its horror. Take your pick. But this creature is undoubtedly a vital part of the game's power—the silent pursuer who shadows James Sunderland through the fog-shrouded town as he searches for his dead wife. A towering, faceless executioner, Pyramid Head is one of the most bizarre, unsettling creatures that's ever oozed out of a human mind, and it still makes my skin crawl.

Pyramid Head was designed by Team Silent art director Masahiro Ito, combining elements of a German WW2-era Konigstiger tank (Ito is really into tanks), and the image of a peculiar pyramid-shaped biomechanical creature he painted while at art school in the 1990s. "The triangle has right angles and acute edges," he says in a documentary about the making of Silent Hill 2. "The sharpness suggests the possibility of pain." According to Ito, some of the development team were hesitant about including the creature in the game due to its strange, unconventional design. "I'm glad I didn't take the advice," he says on Twitter, where he often posts insights into the creation of the character—something I think we can all agree with.

Related: Konami Doesn't Deserve Silent Hill

One of Silent Hill 2's greatest strengths is its restraint, and a perfect example of this is how it introduces Pyramid Head. In the Blue Creek apartment building you walk along a dark, narrow corridor and see a softly glowing red light in the distance. As you draw nearer, the source of that unusual crimson glow becomes clear: it's Pyramid Head, standing completely still, staring at you through rusty iron bars. The corridor is deadly silent except for the wild hiss and crackle of radio static, which lets you know when enemies are near. It's an incredibly powerful moment, seeing this unknowable thing quietly watching you. A lesser game would have introduced a major antagonist like this in a much more obvious way.

Silent Hill 2

But it's a later encounter that is perhaps the most famous—and adds a further layer of disquieting strangeness to the creature. Hiding in a closet, we watch the creature violently abuse a creature cobbled together from mannequin parts, before twitching and convulsing, clawing at its own head, as if trying to prise it open and release something. Before it can, however, a terrified Sunderland fires his pistol and scares it away. This is one of the most memorable moments in the game, being both deeply disturbing and incredibly weird. The uncanny way the creature moves, and the lurid violence of his attack on the mannequin, instantly cements in your mind that this is a video game monster like no other.

Like most things in Silent Hill 2, Pyramid Head is thematically interesting too. The game's story and mythology are open to interpretation (another of its strengths), but it's generally accepted that the creature represents Sunderland's guilt and desire for punishment. Creatures in Silent Hill are manifestations of a main character's tortured psyche, which makes Pyramid Head a very personal demon. This is another reason why it's such an effective monster. It isn't just some supernatural creature from the deep, dark woods whose origin is ultimately meaningless: it's a product of his own mind, and it knows all the bad things he's done. Silent Hill 2 takes the idea of battling your demons and makes it terrifyingly literal.

Silent Hill 2

It's for all these reasons—plus the fact it's just an extraordinarily unique and surreal piece of character design—that Pyramid Head is still a hugely popular, enduring character. Two whole decades may have passed since Silent Hill 2 made its PS2 debut back in the fall of 2001, but no other monster in this medium has come close to matching the sheer otherworldly terror of Masahiro Ito and Team Silent's eerie, provocative creation. Not even idiotic cameo appearances in kart racers, pachinko machines, and bad Silent Hill sequels can take that away, despite Konami's best efforts to turn the character into a garish mascot. Pyramid Head is a true one-off, and I don't think we'll see anything quite like it ever again.

Next: Triple-A Gave Up On Horror, But This Japanese Indie Studio Is Keeping The Dream Alive