Halloween Spectacular of Spooky Doom

Plot:
Dib shows up late for class on Halloween, blaming his lateness on periodically sliding between dimensions where aliens and ghosts roam. The rest of the class deems him crazy and he is placed in a mental asylum. There he is sent back to the nightmare world and is taken out of his cell to be taken to the horrible leader of the Halloween world. Presently he slips back into reality. After escaping, he tracks down Zim (who is convinced trick or treaters are real monsters after his 'blood candy') and drags him into the alternate universe. It is expalined by what appears to be a nightmare version of Dib that the horrible nightmare world exists within Dib's very own gargantuan head where grotesque, horrifying Nightmare versions of Gaz, Membrane, Ms. Bitters (the monstrous leader, in fact) and even Johnny The Homicidal Maniac stalk about. Having already conquered her world, Nightmare Bitters plots to leave Dib's head with the other monsters and conquer his world. Meanwhile, GIR has been instructed to stop the trick or treating kids from coming to the base, which he does... in a fashion.

Eventually, Dib and Zim escape from Dib's head, but Zim is thrown into his fence and gets injured. The aftermath of GIR's servitude is revealed: little kids are all lying about, injured, while GIR, having eaten all of their candy, is a bloated mass. Nightmare Bitters' head pops out of Dib, ready to conquer, but recoiles when she sees the hideous mangled children in costume, and a very bloated and grotesque GIR in his dog suit. She returns to the world inside Dib's head. Dib starts to walk off, but returns for a lollipop nearby.

in my opinion to those who are not usted to the content I think people would find this quiet gross.

I may watch this Movie after I have eaten all my Halloween Candy

yeah I think I will too what I dont get is why the mental asylum scene was there in the first place