Lilo faces Mertle in a trivia contest, but an experiment whose spikes cause people to become 99% silly pricks Stitch, making it harder for her to win. Meanwhile, Pleakley holds a therapy session to tame some of the experiments.
When Nani tries to make everyone eat healthy, Lilo activates an experiment that can cook up delicious food. She soon realizes the evil side effects of the experiments cooking, and Nani must rescue Lilo and Stitch before it's too late.
Lilo throws a "Lilo's Not Weird" party to try to win a new girl named Victoria over as a friend, but a two-headed experiment swaps Lilo's and Stitch's bodies, causing difficulties in throwing the party.
Lilo competes against Mertle to sell the most chocolate bars for the halau hula, fighting over and using Stitch's fast-talking "cousin" Slick to help either of them.
Lilo finds an experiment that allows people to skip 10 years into the future. Wanting to grow up and not be controlled by Nani, she uses the experiment, but things go from bad to worse as she realizes what happens each time she uses it.
Lilo finds an experiment that when worn resembles a crown and causes all others to obey their every command (except experiments designed after its creation) but she soon realizes that absolute power isn't as fun as it sounds.
Lilo discovers an experiment designed to plan and execute mischievous practical jokes. She uses him to get even with her substitute hula teacher, who she thinks is out to get her but soon realizes that he's not as bad as she thought.
Victoria becomes afraid of a bat-like experiment after being attacked. She thought it was a vampire. Lilo comes up with a plan to capture it and turn it good.
Lilo, Mertle, Stitch, Pleakley, and Jumba go on a hike to prove the Night Marchers exist. Along the way comes an experiment that produces a loud, high-pitching shriek.
Lilo and Stitch team up with Jake Long and his friends to stop Gantu from capturing a shape-shifting experiment. Lilo tries to use the experiment to win a skateboarding contest to impress Keoni.
The Proud Family comes to stay at Jumba and Pleakley's "Bed and Not Breakfast", only to become victims of an argument-inducing alien experiment. Gantu and Suga Mama square off in a wrestling ring.
Lilo finds a wish granting experiment and tries to use it to make David more attractive to Nani in hopes of having a more normal family but runs into trouble with the experiments very literal interpretation of wishes.
With Lilo distracted Jumba and Pleakley are left to capture an experiment designed to create typhoon-like winds. Jumbas machine causes it to grow to a massive size they now have to figure out how to shrink and capture the experiment.
Lilo captures a bug-like experiment for her bug city, but it has the ability to turn any living creature into a bug. She, along with Stitch, Jumba, and Pleakley, have been turned into bugs and must find their way back before it's too late.
Lilo finds an experiment capable of listening in to others conversations but soon realizes that without the whole context the wrong conclusions can be reached.
The Recess (1997) gang are on vacation in Hawaii, but Experiment 285 is on the loose, causing Vince, Mikey, and Stitch to abandon any and all forms of work. Lilo must stop 285 and Hämsterviel's new experiment locator satellite without Stitch before Gantu succeeds in catching an experiment.
Jumba's membership in E.G.O. (Evil Geniuses Organization) is threatened because his evil experiments are acting good. Second half of an episode consisting of two ten-minute segments, the other half being "Mrs. Hasagawa's Cats".
When Lilo and Mertle are forced to work together to find buried treasure, an experiment appears that binds together uncooperative people with indestructible, rubberlike slime.