It's Hallowe'en! Lilo has dressed up as a 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 it's way to Kaiaulu Hale's Hallowe'en party, and is terrifying everyone. Can Lilo and Stitch stop 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?

Stitch doesn't know how to take care of anything, or things that don't belong to him. He's already got Nani in trouble at the Rental Shack, by breaking the Shake Machine. However, when Richter turns up and is causing earthquakes, will Stitch be able to stop him breaking everything... Even his favourite ball?

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?

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.

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.

Experiment #258 - Sample #258 is activated. #258 is a sound experiment, that records sounds and plays them back to people, like a sample. Meanwhile, Stitch is worried about getting his shots.

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!

Stitch won't listen to Lilo's advice about trying to see the good in people, and will go to any lengths to stop him capturing an experiment pod, including racing to a neighbouring desert island, with Lilo, Jumba and Pleakley in tow. But after the camp of the 'hunting parties' are destroyed, Stitch and Gantu blame each other. Turns out it's an experiment. Who will capture Splodyhead?

It's Lilo's birthday, but no one has remembered. So, she decides to give herself her own party. However, during the day, Experiment #303 is activated and wipes Lilo's, Stitch's and Gantu's memory. Lilo and Gantu, who think they are Martha and Lenny go after Stitch, who has returned to his natural destructive programming, and so they think is a criminal.

A new show called 'Look at This!' is going to be broadcast lives in the Birds of Paradise Hotel, and everyone is excited, except Lilo and Stitch. At the same time, Experiment #383 is activated and is a hynotic experiment. Hamsterviel sends Gantu after it to hynotise everyone who watches the episode of 'Look at This!'. Things soon break into chaos when Lilo and Stitch capture Swirly from Gantu and take him home, ending up hynotised, and Swirly is recaptured. Will Lilo and Stitch realise who they are? Will they recapture Swirly and give him his one true place?

Pleakley's mother is badgering him about finding a wife, and has even found a perfect candidate on his home planet, so Lilo comes up with an idea: To tell his mom he is already engaged to a human. But Pleakley's family turn up on Earth, so Pleakley must put on a fake wedding, passing Nani as his bride-to-be. But Experiment #032 has turned up, Fibber, and will beep whenever someone is lying. So, as Pleakley tries to plan his fake wedding, Lilo and Stitch have to prevent Fibber from giving away the game.

The Hula Girls have ditched Mertle for Lilo, and consequently, Lilo neglects Stitch to hang with them at the Kauai Medieval Festival. So, when Experiment #586 is activated, Stitch needs someone to capture it with. And who does he team up with? Mertle. Strangely, Stitch and Mertle are having fun trying to capture the metal eater, but this ends when it storms the Medieval Festival.

Lilo finds the pod for Experiment #509, which is a plant experiment. Lilo wants to activate to find it's true place, but Jumba won't let her and locks it up. However, when she makes a bet with Mertle, she breaks the lock and activates #509 and dubs it Sprout. But things get out of control at the Kauai Town Fair, and Stitch has a showdown with a cowboy.

Lilo is going to perform a Hula Dance, but gets angry when Stitch gets in her way. He runs away and finds Experiment #345, Elastico, who is performing at a local circus. Gantu arrives, though, and steals Elastico. The Ringmaster lets Stitch take Elastico's place. He invites Lilo to visit him, but she refuses. Soon Elastico escapes Gantu and returns to the circus, and Lilo needs Stitch to dance, so has to look for him. But which ohana will Stitch choose?

Mrs. Hasagawa is watering her vegetables innocently one morning. However, she activates Experiment #613, Yaarp, which is designed to destroy buildings with it's sonic blasts. Lilo and Stitch are hot on it's trail, when it yarps, and because of Stitch's super hearing, Stitch is temporarily deaf. So, when Jumba says only someone with no ears could be safe from Yaarp, Pleakley is on the stage as an Experiment Hunter. Pleakley catches Yaarp, but Stitch's plan to deter Gantu away from the hunt goes wrong, and he captures Stitch. And now he is offering Lilo a trade: Stitch for Yaarp.

Stitch has been recently very successful at capturing and repurposing the Experiments, but it's gone to his head. He thinks he's too good for everything and is being a royal pain. But things are set to change when Pleakley goes into Jumba's ship and sees an experiment pod with the number '627' on it. Jumba has been making a new experiment. Luckily, it's in containment. That is, until they leave the ship and it escapes! Now it's employed by Gantu and Stitch wants to prove he's better than it. But he just gets beaten, and as 627 can't be turned good, Lilo and Stitch are in trouble...

In a trip to the observatory, Lilo and Stitch overhear Cobra telling an astronomer about a huge asteroid heading towards Earth. Lilo and Stitch go around Kauai telling the people to evacuate with them onto their ship. Stitch also warns his cousins. However, only 6 Experiments - Digger, Swirly, Hammerhead, Sparky, Spooky and Kixx - and a surfer from the beach arrive at the ship. So, Stitch comes up with a new idea; Digger will drill a hole to the center of the asteroid, it can be smashed. Things seem to be going to plan, but they soon find out something lives on the asteroid, and their plan comes crashing down.

Experiment #025 - Topper Stitch is having his first Christmas on Earth, and Lilo is trying to teach him about the holiday. But when Stitch sees an unactivated pod fall into a gift in the mall, he goes crazy trying to track it down. Soon he ends up stealing every gift on the island, and Lilo thinks he has become greedy. However, the truth comes out... But can they find the Experiment pod?

Experiment #228 - Melty Lilo makes an idiot of herself in front of Keoni, so she and Stitch decide to use Jumba's Time Machine to go back and change the past. However, she may have fixed her problem, but she creates a bigger problem when Stitch destroys the Birds of Paradise hotel chasing Experiment #228 and Nani is fired from her new job. Will things work out?

Experiment #604 - Houdini Stitch and Pleakley are working up a terrible magic act to perform at one of Mertle's parties, so Lilo secretly helps them out by activating Experiment #303, Houdini, which can make things disappear and reappear with a blink of it's eyes. But when Gantu crashes the party, things go wrong, and Stitch is made invisible and Houdini gets away. And just to make things worse, Mertle's aunt, who is a big LA producer, wants to make Stitch a star because of his magic act, but only Lilo, Jumba, Pleakley and Houdini know it is phony.

Experiment #602 - Sinker Lilo is having high hopes for Keoni and his sailboat entry in a regatta, until his boat is sliced in half by Experiment #602. Soon Lilo, Stitch, Jumba and Pleakley are stowaways on a cruise ship. So while Pleakley is fascinated by shuffleboard, and Stitch digs into the buffet, Lilo must find the ship's Captain and warn him about Experiment #602.