Experiment #375 has been activated; a phantom-like experiment that can inhabit and animate inanimate objects. So when it gets loose in the family's house, it inhabits Lilo's toys and creates all sorts of mess, for which Stitch gets the blame. Can they catch the real culprit, or will Stitch be blamed for everything?

Lilo is upset when Mertle gets a nice-looking fancy hairdo. But when she encounters a hair-eating experiment, Clip, she decides to get her revenge on Mertle by placing it in her bedroom with the plan of ruining Mertle's hair. But the plan runs amock and the experiment eats Mertle's mom's hair instead, and now the experiment is loose on the island. Now Lilo and Stitch must track down the experiment before everyone goes bald!

Lilo and Stitch have captured a new experiment, #254. He is insanely cute too, and charms all of Lilo's friends. Stitch is jealous though, so at the first chance he gets, he lets Gantu capture him. As luck would have it, 42 hours after the experiment's activation, Mr. Stenchy releases such a foul stench, the area he releases it in is uninhabitable for decades. But without knowing of when Mr. Stenchy was activated, how will Lilo and Stitch save him before he releases the smell?

Experiment #606 - Holio It's Mertle's birthday, and she's got a brand new bracelet! But Lilo soon finds out it's got an experiment pod, though she doesn't know the number. So, Stitch goes undercover for her, and discovers it is the pod for Experiment #606. Now Lilo must get the pod back as quickly as possible; as #606 is an experiment that can suck in the entire world!

Experiment #300 - Spooky It's Hallowe'en! Lilo has dressed up asa gory character, while Nani is trying to get everything ready for the trick-or-treaters. Sadly, the house never gets any trick-or-treaters, but Nani wants to fix this. However, Experiment #300, Spooky, is activated, and it can turn into anyone's greatest fear. So, it makes its way to Kaiaulu Hale's Hallowe'en party, and is terrifying everyone. Can Lilo and Stitch stop it?

A bird has discovered a strange blue ball in her nest. After deciding she doesn't need it, she discards it into the river running below her tree. It turns out it's #520's pod, and it activates. Now the experiment is wreaking havoc over the island with it's huge behind by bouncing and shaking the ground. So, Lilo and Stitch must capture it, but Gantu is on it's trail too.

Mertle has got a new dog; Gigi. Little does she know, it's really Experiment #007, a dog that can keep everyone in the neighbourhood awake with it's loud yapping. So, Lilo and Stitch must protect it from Gantu, but have to go to a dog show to do it.

Experiments #501 and #502 are both activated at the same time, a water sprayer and a lava sprayer. Unfortunately, Lilo and Stitch are having some problems with each other, and soon decide to split apart, with Lilo teaming up with Pleakley, and Stitch teaming up with Jumba. Can the 2 capture the experiments without their partner?

When Experiment #601 is activated, things are looking bad, as he is beating up the islanders. Stitch is ready for it, but when he eats the combination of a left tennis shoe and macadamia nuts, it creates a toxic poision, which erases all of his super abilities. Now Lilo has to retrain him from scratch, but Stitch doesn't like the idea.