[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/runaway_brain_mickey.jpg]]
[[caption-width-right:350:Mickey Mouse GoneHorriblyWrong.]]

* Just the commercials for the short alone could terrify the young generation of that time.
* The [[https://www.youtube.com/watch?v=GwOLFdwMZw0&t=3s intro]]. "Hey! Mickey's got a new short! Looks like it'll be fu- [[JumpScare HOLY SHIT WHAT THE FUCK JUST RIPPED THE TITLE CARD OFF?]]"
* [[FamilyUnfriendlyDeath Dr. Frankenollie's death]], when Mickey as the monster picks up his charred body after the experiment, [[StrippedToTheBone his skin disintegrates revealing a skeleton, then the skeleton disintegrates]].
* The appearance of Julius in Mickey's body. Just the fact that he is a monster inside a beloved cartoon icon's body is enough to scare some kids. The fact he spends his time trying to molest the same cartoon icon's girlfriend while using his body is even worse.
* Julius in his own body, a hulking giant with MoreTeethThanTheOsmondFamily, looks pretty terrifying too and has all his viciousness in tact. When Minnie rejects his advances, he tries to eat her whole!
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