- Early concepts shows that Lotte can absorb spirits to gain power.
- Sucy, really, if you don't find her to be a source of humor. She has a penchant of subjecting people to experiments that the Geneva Convention would condemn and genuinely enjoys making people suffer via her pranks, which are actually sometimes pretty dangerous. Not helping is her constant Creepy Monotone, generally unsettling demeanor, and willingness to use people for her own gains (i.e. using Akko and Lotte—two strangers she just met—as bait for the dangerous cockatrice just so she can collect some of its poison).
- Sucy the Mad Scientist loves coming up with new, mostly deadly, potions and then testing them on unlucky victims, mainly Akko (pictured above).
- Speaking of Sucy the Mad Scientist, episode 8 has Akko go inside Sucy's to find out how to cure her after she went into a coma from drinking one of her potions. In her dream world, Akko meets every aspect of Sucy's personality and tries to find the original one. During her stay in the dream world, she is put into a Kangaroo Court that tries to purge Sucy's other personalities, and then the Sucy that Akko rescued turns into a bloodthirsty Eldritch Abomination that devours the other personalities and threatens to take over Sucy's original personality.
- The "Wild Hunt" in episode 18 features ghosts: they are vaguely human-shaped, featureless grey entities that look unsettling if compared to the mostly goofy or bizarre faeries and magical creatures seen throughout the series.
- Vajarois the Grieving's plight. A young princess was so depressed and devastated over the loss of her friends that she swallowed a seed that would make her perpetually sad. And—instead of helping a grieving soul move on to the next life—the witches of Luna Nova decide to use her as little more than some entertainment display for an annual festival. All the while, she's constantly remembering how painful it is that she lost her friends. Kind of no wonder why she's always crying and wailing...
- Episode 24's ending. The cuts between happy Akko and friends, a giant missile and the rioters and politicians looking confused and scared are already unnerving, but the ominous beeping sounds and the eerily calm BGM make them outright creepy.
- Appleton Academy's "witch hunting" culture and protocols. Apparently, upon undeniable evidence of the presence of a witch, the students can immediately don black executioner's hats, put up witch hunting wanted posters, and have access to a working torture room complete with implements and equipment, like an iron maiden. More unnerving than the fact that this exists is probably how eager the students are to put a witch to "trial."
- Noir Rod. While assuming a dragon form upon gaining sentience is already creepy, it soon gets worse after possessing a missile upon nearly being killed by Akko's Shiny Arc. However, when it is about to destroy a nation by nuking itself up, it progressively assumes a more monstrous serpentine form which suggested that it transcends into a Beast of the Apocalypse.
Nightmare Fuel / Little Witch Academia