In this Halloween episode, an experiment that can morph into a person's worst fear is discovered. It is revealed that Mertle, Elena, Teresa and Yuki's worst fear is seeing Lilo without her head; Moses' worst fear is spiders; Lilo's worst fears are clowns and an abandoned house; Stitch's worst fear is water; Nani's worst fear is losing Lilo (especially hearing Cobra Bubbles say he came to take Lilo away); Jumba's worst fear is his ex-wife; and Pleakley's worst fear is his mother.
- Moral: If you face your fears, you'll likely get over them.
- Spooky bears a great resemblance to Oogie Boogie from The Nightmare Before Christmas.
- Spooky has glowing, olive-green eyes instead of black ones like most of the other experiments.
- Spooky's disguises can be seen through them by his glowing green eyes and hissing voice.
- Jumba also referred to Spooky as "X300" and mentioned that his impression of Jumba's ex-wife is frightening.
- Lilo revealed that she doesn't like clowns or broccoli.
- Mertle shows a little compassion when she openly admits that Lilo should attend the Halloween party, as well as confesses that Lilo was right about her, Elena, Teresa and Yuki's costumes being too boring, although Yuki does point out that Mertle forced them to do this in the first place.
- Stitch is revealed to hate organic lemons after tasting one. However, in later episodes, he is shown to like most other fruits and vegetables.
- Nani is the only character to have an emotional fear, as opposed to an irrational one.
- It would seem that, according to Spooky's impression of Jumba's ex-wife, Jumba's species naturally has poor grammar with regards to English.
- Lilo and Stitch use the song "Aloha `Oe" from the original movie as a coping tactic to overcome their worst fears.
- Gantu, Reuben and Hämsterviel do not appear in this episode.
- In spring 2004, Disney Channel held an online poll that asked viewers for their favorite experiments and episodes from Season 1 of the series. According to the top 10 results of that poll, "Spooky" was the #4 most popular episode and experiment.