While the punishments from the kids onto the Eds usually leave them cowering in fear, the fact that all three of them are panicking and trying to run for their lives, visibly scared the whole time at the start of The Movie is unsettling; especially with the kids actually pissed off enough to try and murder them.
The kids's injuries are also pretty freaky. Jonny has a bear trap on his head, Kevin looks like he was set on fire, Nazz's hair has been partially shaved off and she's naked in a magician's box, and Rolf has most of his torso torn off! What in God's name did the Eds do?!
The Ed's scenes of panic are all uncomfortable to watch in their own way. Ed is acting like they've caused The End of the World as We Know It, Edd is writing a letter to his parents saying they've done the most unholy sin imaginable and has to keep pausing to cry, and Eddy is down right hysterical.
Towards the end of the movie, Kevin states the Eds have to "pay with their lives", which means that at least he was going to actually commit murder.
Doubles as Fridge Horror, as Kevin now hated the Eds enough that getting life in prison or the death penalty would be worth it.
The scene where Eddy and Ed seemingly sink in quicksand/mud, even though it's only a prank, it was surprisingly close to an actual death scene.
Double D's reaction to them faking their deaths. He is extremely pissed at them for scaring him that much. Sure he got mad in the main show, but here he is legitimately pissed off at them to the point of which he's willing to go back to the Cul-De-Sac rather than spend another second with Eddy and that he actually gets into a fight with Eddy over the scams, and the two actually physically duke it out. What makes it worse is that Ed watches the entire scene in utter fear and he's powerless to do anything about his two best friends fighting.
Ed: "The evil dark side has consumed them both! Trouble! Bad! Pain!"
Eddy's brother in general, and particularly the smile and stare he makes (pictured above). It stretches to around half his face. Worse, he's an Ax-CrazyPsychopathic Manchild who loves torturing children, and the only one in the series that really deserves these tropes. His Evil Laugh when he twists Eddy's leg as well. It's not a comical laugh, but a realistic, twisted, demented laugh. Even the music that plays during the scene is pretty freaky too, as it is a sinister tune mixed with an electric guitar. Listen to it here.
The kids all react in absolute horror, to the point that Kevin, of all people, gets over his fear of Eddy's Brother and tells him to lay off.
The way Eddy brokenly begs for his brother to stop beating him is extremely unsettling.
Even the Kankers are utterly appalled by his cruelty.
When Rolf thinks he's found the Eds, he takes out a pitchfork and starts stabbing the air.
The look on Ed's face as he decides to let the door off its hinges looks frighteningly familiar to the Nightmare Face he made back in "Little Ed Blue".