[[caption-width-right:273: Sonic ? Is that... you ?]]
* ''Sonic's Scream Test''. Eyes aren't supposed to look like that... although these ghosts wouldn't look too bad in Paranormal Activity or any other horror film.
** [[https://youtube.com/watch?v=xVYqGtsbPcQ Don't forget about that moment where]] [[DemonicPossession Amy gets possessed!]] [[NotHerself Sweet]] [[NightmareFace dreams]]...
* Episode 27 showing Eggman's iconic method of placing animals into his badniks ''while they are still conscious, [[AndIMustScream frantically screaming and trying to get out]]''. Granted the blow is lessened when you realize the badnik is [[MinionWithAnFInEvil E-102]] [[IronWoobie Gamma]].
* For some people, Dark Super Sonic. OH YEAH, [[PunctuatedForEmphasis ''The. Dark. Super-Sonic.'']] Even Eggman was worried and unsettled about it, to the point of convincing Sonic to [[GetAHoldOfYourSelfMan calm down.]] For all he knew, Dark Super Sonic might've gone on to kill the rest of them.
** It's Especially scary, because, Sonic is normally a pretty laid-back guy; seeing him get [[RageBreakingPoint so angry]] [[SanitySlippage to the point]] where he transform into '[[SuperPoweredEvilSide some monstrous kind of self-supreme being ]]' (via Jekyll and Hyde) who's dark, [[SuperStrength super-powerful]], and also eventually AxCrazy, that's [[BewareTheNiceOnes uttery frightening]].
** In the English Dub, Sonic's voice doesn't change to much aside from sounding very pissed about what happened to Chris and Cosmo. Japanese Dub, however, Sonic's voice turns dark, very quick. After seeing a terrified Cosmo and unconscious Chris, his voice trembles with shock at first, but it soon becomes [[TranquilFury silently indignant]]. And when the carnage begins, he [[ScreamingWarrior screams bloody murder]] as he [[UnstoppableRage rips the robots apart.]]
*** This is the same reason why [[AlterEgo Super-Sonic!Iblis]] (from the "Archiel Comics") is terrifyingly unsettling, and also similarly freaky… [[spoiler:tag Because it's Super-Sonic presumably fused with Iblis (Hence on why they refer to This BadFuture version of Super Sonic as a reincarnation of the same entity), Scrounge and even Melphieus also.]] (It's even implied that he killed own [[FaceHeelTurn beloved one successfully and]] ''[[MoralEventHorizon mercilessly]]''.)
* [[spoiler:The three-headed plant dragon that Dark Oak, Black Narcissus and Pale Bay Leaf [[FusionDance transforms]] into is absolutelty scary in appearance. Not only that, near the ending of the show, they litterely ate Sonic alive!]] [[OhCrap Cue the shots of the whole cast watching with outright fear and shock!]]
* Episode 60 had an eerie tone to it, even going so far as to have one [[UncannyValley giant creepy eyeball watching over Sonic, Knuckles, and Amy through most of the episode,]] and the disembodied ScaryTeeth floating in the air near the end. What's even creepier was that the [[DarkCastle "scary" castle]] they were in for the whole episode was indeed self-sentient. Granted it WAS just a Metarex, but still...
* The Metarex in general are pretty messed up. They [[ApocalypseHow destroy their own planet, and then attempt to wipe out any life that isn't plant life]]. They even kill their own members if it helps them, and Dark Oak [[AdultFear really has no concern for his (implied) daughter, Cosmo]].
* Episode 73. [[spoiler:It's basically Shadow hunting down Cosmo for the most part and if you're familiar with his strength, speed, and capabilities, then you know for sure you can't stop him from causing harm even if you tried. In fact, this is exactly what the Sonic cast was doing only to get pushed aside so easily. Of course, at the end of the episode, the crew was able to stop Shadow from running off away with Cosmo... but still the thought of [[BloodKnight the ultimate life form trespassing in your headquarters with the intent of ''harming you or a best friend'']] is [[ParanoiaFuel fear-incarnated.]] ]]
** The worst part? [[spoiler: They finally get Shadow off the vessel, via using the Chaos Control cannon. They think they're safe... and then [[ImplacableMan Shadow]] arrives again. It's just due to coincidence that he didn't murder the entire crew.]]