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Nightmare Fuel: Malcolm in the Middle
In one episode, Malcolm decides to hold everything in, becoming 100% agreeable. By the end of the episode, his internal monologue has become a screaming demonic voice, and he spits up a large amount of blood due to developing a severe ulcer.
Francis hunting down the mythical rat "Rose Marie" and instead ending up completely enveloped in her offspring. As funny as it is, you can't help thinking you'd scream like that too if you were trapped in a crawlspace and covered in live rats.
Craig's helper monkey going insane and trying to kill him and Hal.
Craig: He watches me while I pretend to be asleep.
Malcolm, Reese, Dewey, and Stevie being locked in a closed amusement park in the middle of the night then being chased by a crazed security guard.
Let's face it, the show runs into this trope very frequently. It comes with the Black Comedy.
Malcolm getting screamed at by his girlfriend's over-protective father when he finds out he isn't just her tutor. Malcolm is so terrified that he curls up into a fetal position.
In one episode where Lois takes the TV out of the boys' room for ruining her dress(which they didn't do), Lois finds out that they carried it back while she wasn't looking. Then this happens...
Lois and her mother. Imagine being raised by people this cruel, manipulative and abusive, who simply do not care how horribly they damage their offspring. Lois' mother is actually WORSE than she is, but not by much. We can only hope that Malcolm never becomes President, because imagine what an individual that damaged would do with access to nuclear weapons.