- The Dark Ocean, and the creatures living in it.
- The Divermon in Episode 13 who live near the Dark Ocean want Kari to have a child with them. One of them even calls Kari a "virgin".
- The Digimon Emperor's Villainous Breakdown.
- Oikawa's creepy email to young Ken in "Genesis of Evil".
- Arukenimon appearing in Ken's room in the middle of the night in "If I Had a Tail Hammer".
- Arukenimon and Mummymon abducting children to implant with Dark Spores. And the children themselves, even before getting the Dark Spores.
Child: Oh, hey, mister. Guess you're all alone too. You wanna be friends?
- What makes it worse is the build-up; Right after some light-hearted action with the Children, we cut back to a playground in Japan; a lone child is sitting on the swings, and when we cut in for a closer shot, Mummymon is there too.
Mummymon: …(Slasher Smile')
- Oikawa's hallucinations in the cemetery in "BlackWarGreymon's Destiny".
- MaloMyotismon torture-murdering Arukenimon and Mummymon.
- His design is a bit creepy as well, especially his shoulder cannons that open like organic jaws.
- The completely surreal final battle against Cherubimon in Hurricane Touchdown/Supreme Evolution! The Golden Digimentals.
- Diaboromon's return in Revenge of Diaboromon shows that the virus Digimon is just as dangerous as he was in Our War Game, staying one step ahead of the Digidestined and achieving his goal of materializing in the real world as Armageddemon, handily beating Omnimon and Imperialdramon.
- In the English dub at least, the fake Blossomon in the episode where Silphymon debuts. Not only is it bigger than usual- unlike the other Black Tower-created Digimon, this Blossomon never talks or even makes human-created grunts. Oh no- it roars a nightmarish roar. Even In-Universe, this roar actually traumatizes Kari out of digivolving Gatomon to Angewoman, just as she's about to.
- The unexplained apparition of Devimon.
- It actually is explained, just not particularly well. Though that doesn't make Devimon's presence any less frightening. Devimon's appearance in the Dark Whirlpool is a fragment of his former self who the Digimon Emperor hunts down to gather his data to create Kimeramon. The implication of Devimon being here is that either he's been reviving all this time, or that he's spent three whole years alive and reforming after Angemon beat him. And then when his data is used to complete Kimeramon his personality turns out to have survived and his evil influence turns Kimeramon into an unstoppable rampaging berserker that takes Magnamon, a Royal Knight with power on par with a Mega Level digimon, to finally be put down. Even three years later, the original Big Bad of Digimon is still terrifying.
- Daemon's entire appearance. A mysterious being with enormous amounts of power whose very presence gives off a creepy Satanic vibe and can only be sealed away rather than defeated. His appearance may have been short, but it sure as hell was memorable.
Daemon: The powers of darkness are not to be trifled with!