Ep 18. Yaarp

In Lilo & Stitch: The Series season 1 episode 18 titled "Yaarp," Lilo and Stitch meet a new alien experiment that has the ability to create sonic blasts. However, they soon realize that this experiment, named Yaarp, is malfunctioning and causing destruction wherever he goes due to a missing on/off switch. Meanwhile, Jumba and Pleakley are mistakenly incarcerated in a zoo after being mistaken for escaped animals. Lilo and Stitch must find a way to fix Yaarp and rescue their friends from the zoo before it's too late.

The episode begins with Lilo and Stitch playing their favorite game of catching falling coconuts while Yaarp, the latest experiment, watches from a nearby bush. Yaarp, who resembles a giant blue jackhammer, has the power to create sonic blasts that can destroy anything in his path. However, as the duo approaches him, Yaarp shoots a sonic blast directly at them, causing Lilo and Stitch to take cover behind a tree. The experiment then runs off into the jungle, leaving Lilo and Stitch confused and bewildered.

Meanwhile, Jumba and Pleakley are on their way back to Lilo's house when they get lost in the jungle. To make matters worse, a zoo truck passes by and assumes they are escaped animals. Jumba and Pleakley are soon captured and locked up in separate cages at the zoo, much to their protest.

Back at Lilo's house, Lilo and Stitch are trying to figure out why Yaarp attacked them. They soon discover that Yaarp is malfunctioning and doesn't have an on/off switch like the other experiments. Lilo and Stitch then recruit Cobra Bubbles, the social worker, to help them fix Yaarp. They discover that Yaarp's power source is depleted and needs to be charged, but when they try to charge him, he accidentally hits a switch which amplifies his sonic blasts, causing chaos in the neighborhood.

Lilo and Stitch realize that they need to find Yaarp's missing on/off switch, but have no idea where to look. They decide to search the jungle for clues and eventually stumble upon a hidden cave filled with mysterious alien artifacts. They examine the artifacts and soon discover that the missing switch is actually a key that unlocks a secret door in the cave.

Lilo, Stitch, and Cobra Bubbles use the key to unlock the secret door, which leads them to a hidden laboratory filled with advanced alien technology. They discover that the laboratory belongs to Gantu, a notorious alien bounty hunter, and that he has been secretly tinkering with Yaarp in an attempt to make him a more efficient weapon. Lilo and Stitch are shocked and appalled by Gantu's actions and immediately decide to rescue Yaarp and put an end to Gantu's evil schemes.

The trio sneaks into Gantu's laboratory and successfully rescues Yaarp. However, Gantu manages to escape, promising to return and seek revenge on Lilo and Stitch. Meanwhile, Jumba and Pleakley manage to break out of the zoo with the help of a new friend they made, a meerkat named Timmy.

Back at Lilo's house, Lilo, Stitch, and Cobra Bubbles successfully repair Yaarp's power source and install a new on/off switch on him. Yaarp is now fully functioning and much less destructive, and Lilo and Stitch are happy to welcome him into their 'ohana of experiments. The episode ends with Jumba and Pleakley returning home and sharing their crazy adventure with Lilo and Stitch, who can't wait to hear more.