Mawaru Penguindrum/Nightmare Fuel

This series by Kunihiko Ikuhara started as a rather... weird but humorous show. But as time went on, the weirdness increased, and well. . .

• In episode 8, Ringo serves Tabuki a drugged montblanc and attempts to rape him but Shouma shows up in time to stop her thankfully.
• Tabuki is this in spades, in episode 11. It's bad enough when Ringo's Love Potion actually works on him, but then he starts acting like a frog ("ribbit" included) and making really horrible Nightmare Faces... as well as when he also punches through a door to try and get Ringo back inside, presumably to rape her after she decides to not have sex with him.. Be Careful What You Wish For, Ringo...?
  • On the other hand, Yuri's arrival a well as her weirdly... calm disposition defused more than a bit of the scariness.
• For some, Mario Natsume is FREAKING CREEPY. The first thing he said in the series is "SURVIVAL STRATEGY!", he has his own Penguin Hat, shows absolutely NO emotions otherwise, freaks the shit out of the otherwise Hot-Blooded Kanba when they meet without saying a single word, is the center of his sister Masako's "Project M"...
  • Even worse in episode 16. When he finally gets to talk some more, it's because his grandfather's spirit is using him as a Soul Jar. AAAAUUUUGH.
• Sanetoshi's black bunnies. Holy shit.
• Episode 14. Yuri drugs and tries to rape Ringo. NO ONE COULD SEE THAT COMING.
  • Even worse is how Yuri is mentally broken at that point and does this while mentally repeating how much she hates herself due to her body issues and loneliness.
• And then we have episode 15. First there's Ringo's extremely erratic behavior and words as she calls Shouma while drugged and about to be raped by Yuri, which causes Shouma to freak out. And then we have Yuri's past as the victim of a rather... special, to say at least, type of physical abuse (and maybe sexual as well) from her terribly creepy father. Who also happens to bear some vague resemblance to Touga's rapist stepfather from the Utena movie. GAH!
• Episode 17 and 18 have Tabuki as the freaking Master of this as he goes from kind and slightly off-kilter school teacher to totally unhinged would-be killer who takes Himari hostage and almost gets her and Kanba horribly killed.
  • And this is without including the whole concept of the Child broiler. Kids, if your parents don't like or want you , they can perfectly send you to this place where you will be erased from existence. Sweet dreams!
• Episode 21, oh Gods. Kenzan and Chiemi were Dead All Along. Not only we see their corpses (already a pretty bad sight), but then we realize that Kanba was hallucinating when we saw him talk to them...
  • Not to mention, Kanba beating the shit out of Shouma when he calls him out is just... wrong!
  • And also, the reporter and either Tabuki or Yuri (or maybe both) getting getting bridges dropped on them for getting way too close to the truth. Courtesy of Kanba, to make it worse.
    • Well, it's revealed to be Yuri's crazy lover instead of Kanba's doing...which is still quite frightening in itself nonetheless.
• In episode 23, we finally learn how Momoka died/disappeared. It's not a bloody scene, but the mere idea of having your body disappear while your soul is sealed away and split into two is not cool.
  • An then we have Kanba and specially Sanetoshi's Death Trap of sorts for Ringo, which has made many people scream for their painful deaths (specially the latter's). Whether you like Ringo or not, there's no real discussion on how burning to almost death to protect the Diary, being Hannibal Lectured while still in flames, and then being left to die in a burning building. is really not pretty.
• In the Grand Finale, Kanba's screams as he starts to be Ret Goned will haunt your memories fo a long, LONG time.
  • Not to mention the High-Pressure Blood...