Nightmare Fuel / Metal Gear Solid: Peace Walker

• The Boss AI's speech dissolves into random phrases while its voice drops into static. Especially near the end where she just screams "Jack!" over and over in a slow, distorted voice. The Boss just should not sound like that. Ever.
• The Peace Walker unit, specifically what would happen if it was mass produced, is also extremely terrifying to imagine. Aside from the fact that it can launch retalitory strikes at countries, or even be tricked into launching nukes at other countries by making it think that there was going to be an attack on the US homeland, there's also the fact that it is equipped with a huge hydrogen bomb so it could sneak into enemy territory and self destruct, most likely obliterating an entire nation. When you remember that Hot Coldman planned on mass-producing Peace Walker throughout Central America (from Belice all the way to Panama), it becomes a lot more horrifying when you take into account the implications of what might happen if he, or some other mass-murdering madman, decided to have all the Peace Walker units stationed in Central America self destruct in their respective countries. In fact, Hot Coldman is the most evil, insane, and depraved character in Metal Gear history, even outranking Colonel Volgin (If he managed to make even an extremely sadistic GRU Colonel who has absolutely no qualms about blowing up countrymen for laughs run for his money, you know that Coldman is bad news.) and, to an extent, even Skull Face (whose horrific actions are of a much more personal nature).
• Whenever the Chrysalis shows up, it always announces its presence by singing a pleasant little tune, even as it machine guns and kidnaps people. It's downright unnerving.
• Paz... To be specific, Paz the "peace-loving pacifist" really wants to unite the world under one will with Cipher and Major Zero. Paz wants to kill Big Boss despite struggling with Becoming the Mask according to her audio tapes, has very few problems launching nukes and framing MSF, was playing Big Boss for a chump since the start of the game, and hates kittens. "Say Peace!"
• There's something completely unnerving about the bosses chirping out stuff like "Chaingun" in their cutsey Vocaloid autotuned voices.
• "Jesus. Coldman guessed wrong. They're gonna go through with it!"
  • If you take too long to stop Peace Walker from launching her nuke:
    Kaz: (at the last 15 seconds) We're too late! Oh God!