Anthony brings a demented-looking Tazmanian Devil-like character out out of the TV into real life and it looks almost real. Then he brings his (false) sister into the cartoon world and robs another of her mouth. The world he creates is demented in and of itself. He also summons a demonic rabbit out of hat. What's worse, he has no idea why people would find his ideas of Toons frightening.
The gremlin standing outside Mr. Valentine's window, which makes his eyes bulge out in a creepy way when he sees it.
The opening to the segment, with him suffering a panic attack in the airplane bathroom. The claustrophobic cinematography, driving, pulsating string soundtrack and John Lithgow's convincing acting are all highly unsettling and do a great job at putting the viewer on edge.
The helicopter accident that killed Vic Morrow and the two kids he was carrying. Vic and one of the kids were decapitated. The actual description of what happened on  is even more disturbing:
The helicopter went out of control.
In the water, Morrow dropped Renee Chen. He grabbed at her but the helicopter's right skid slammed into the child, killing her. Then its whirling main rotor ripped off the middle-aged actor's head and the head, a shoulder, and an arm of 7-year old My-ca.
"That's a wrap!" John Landis shouted through the loudspeaker and the standard, banal words signaling the end of filming day sounded sickeningly incongruous. "Leave your equipment where it is. Everyone go home. Please, everyone go home."