- The Ghostly Trio scare Dr. Harvey upon their first meeting, though this can also count as terrifying:
Stretch: (duelling with Dr. Harvey) Who do you think you are, defilin' our domicile?!Dr. Harvey: (parrying with every word) Doctor! James! Harvey! Your! Therapist!
- Dan Aykroyd in full gear stumbles out of the house. "Who You Gonna Call?...someone else." *runs*
- Casper follows Kat to school. After her classmates give her a hard time, Casper pays them all back by tying their shoelaces together. When the end-of-class bell rings, they all trip and fall to the floor in unison.
- "Uh... boo?" (loud screaming)
- The Up and At 'Em machine, especially with Carrigan and Dibbs.
- The Ghostly Trio use Casper as an accordion, then fling him to the moon.
"[singing] Shine on/shine on harvest moon/up in the sky... [ka-FLING] Bah-BYYYYYYEEE!!!!"
- "It's my party and I'll die if I want to!"
- The Trio draw swords on Harvey and slash the belt off his pants
The Trio: (all together) ALL FOR ONE AND ONE FOR ALL!Stretch: Catch yer pants before they fall!
- Kat and Stretch exchanging insults across the table. When Dr. Harvey tries to urge her off to school, she can't help but make one last parting remark.
Kat: (pissed) Drop dead!Stretch: TOO LATE!
- As scary as the Ghostly Trio looked when they scared Dr. Harvey, you can't help but find it funny.
- Carrigan's scream as she plummets off the cliff.
- Old lady on TV: "A g-g-g-ghooost!"
- Dr. Harvey looking at himself in a mirror, possessed/shapeshifting into different celebs, from Clint Eastwood ("I'm gonna kill you...your mama...and all her bridge-playing friends"), Rodney Dangerfield ("I got a face lift; there was one just like it underneath!"), Mel Gibson (Mel/Harvey just admires his reflection), and the Crypt Keeper, who does the famous Home Alone scream.
- Upon finding Stretch, Fatso, and Stinkie's beds:
- When Casper's uncles are scaring Dr. Harvey, he manages to fend off Stretch and Fatso, but when he reaches Stinkie, he's at a sudden loss of what to do so he just breathes his foul breath on him.
- Amber and Vic attempt to perform a Totem Pole Trench on Kat as a prank at the dance. Suddenly, the Ghostly Trio pop out of the mirror and terrify them. The sudden appearance of Stretch's head and the Evil Laugh nails it, as does Amber and Vic running into a string of lights and falling over, with Vic dragging Amber out of the room.
- Carrigan causing Dibbs to accidentally hit his head when they first enter Casper's father's lab.
- This exchange:
Kat: "A pulse?"