Axis Powers Hetalia/Nightmare Fuel

Belarus scratching at Russia's door and tearing out the doorknob when trying to "become one" with him. Not to mention the close up on her insane facial expression or her repeating "let's get married". Russia, who's pretty insane himself, even cries Tears of Fear.
Anytime Russia goes into Yandere mode. And there's the "Bloody Sunday" strip, in which he finally snaps and starts GUNNING DOWN his own people as they're rioting in the streets ("If they hate me, they're not Russian.") before turning to Lithuania and stating "We don't want children who can't play nice, do we?".
Russia thinks nothing of his heart dropping onto the table in the middle of an Allied Powers meeting. According to him, it just "falls out occasionally".
Paint it, White! gives us a few good ones. For starters, there's the opening scene, with a woman running from a group of Pictonians chasing her. She thinks she escaped and found a police officer...only to find out that he was just turned into a Pictonian himself. She just stands there, terrified, while she herself is converted. Then there's the final fight, where everyone but Italy is converted. It happens slowly, so we get to hear everyone screaming as it happens. And unlike the other people converted, the nations just freeze afterwards, while the aliens walk around them.