Yaarp

Yaarp, A.K.A. Experiment 613, is an illegal genetic experiment created by Jumba Jookiba. He is designed to create devastating sonic blasts from his megaphone-like antenna. His one true place is at Lilo's hula school as an alien invasion alarm and buzzer.

Personality
Yaarp is very friendly, but responds quickly and dramatically to the way he is treated. For example, if he feels intimidated or provoked, he will emit loud sonic blasts. If he feels safe or unthreatened, he will emit small, gentle honks as a sign of trust and affection.

Yaarp, for the most part, is pretty simple and laid-back. However, he is very ready-minded and cautious. Yaarp is a bit jumpy and nervous, sometimes sounding his horn at improper times because something trivial startled him.

Lilo & Stitch: The Series
Experiment 613 was the 613th experiment to be created by Jumba with Hämsterviel's funding. He was designed to use his sonic-blasting ability to shatter buildings and deafen nearby victims. 613 and the other first 624 experiments were deactivated and smuggled to Earth by Jumba during his mission to capture Experiment 626.

All of the experiment pods were released and scattered across the island of Kauai, with 613's pod landing in Mrs. Hasagawa's fruit.

When Mrs. Hasagawa watered her fruit, 613's pod got wet, activating the experiment. 613 captivated a couple on their honeymoon, then proceeded to cause massive chaos using his destructive shock waves.

When 613 was later chased into a store by an earmuffed Gantu, the former was captured in a container, but rescued and freed by Stitch. This unintentionally allowed 613 to escape, but not before emitting a sonic blast that caused Stitch to temporarily go deaf. Gantu then resumed his pursuit of 613 after the latter fled the store.

Due to Stitch's sensitivity to 613's shock waves, Pleakley was hired to try to capture the experiment. After Lilo, Stitch and Jumba attempted to train and condition Pleakley, he was equipped with special gear for catching 613.

While Lilo, Jumba and Pleakley tracked 613 down, Stitch disguised himself as the experiment and served as a decoy for Gantu. Stitch imitated 613's sonic blast to alert Gantu, who donned his earmuffs and pursued Stitch.

Meanwhile, 613 retreated to a cave where he was discovered by Pleakley. When Pleakley unintentionally blasted 613, the latter retaliated using a massive shock wave. However, when a sudden cave-in endangered 613, he was then saved by Pleakley himself. 613 was grateful and kissed Pleakley, who christened him Yaarp.

Pleakley and Yaarp then fled the crumbling cave and made it out safely. Yaarp growled when he first noticed Lilo until Pleakley assured him that she was a friend, causing Yaarp to emit a gentle honk. Unfortunately, Stitch was captured by Gantu (who thought Stitch was actually Yaarp) during the process.

As part of a setup, Yaarp was taken to the local museum for a ransom exchange. When Lilo arrived with Yaarp, the former convinced Gantu that Yaarp was rehabilitated and allowed him to be bartered for Stitch. However (as planned), when Gantu removed his earmuffs and made the trade, Yaarp unleashed a sonic blast upon Lilo's signal, alerting the authorities and forcing Gantu to flee.

Yaarp, after being revealed to the mayor and chairwoman, was shortly after given a one true place as an alien invasion alarm at Lilo's hula school.

Yaarp reappeared in "Elastico" as one of the audience for Lilo's hula dance.

Yaarp reappeared in "Spike" for the Ohana-Rama. He was the scorekeeper for the contest.

In "Remmy", Yaarp was one of the experiments in Lilo's dream.

Leroy & Stitch
In the film's opening Yaarp can be seen greeting Lilo with sonic blasts from his horn.

Later, the first 624 experiments, including Yaarp, were rounded up by Leroy and taken to a stadium to be destroyed. However, Lilo, Stitch, Jumba, Pleakley, Reuben and Gantu arrived before the experiments could be destroyed.

Yaarp participated in the following battle between the experiments and the Leroy clones.

The Leroys soon gained the upper hand in the battle, but were defeated when Lilo, Stitch, Reuben and several other experiments performed the song "Aloha `Oe," which caused the Leroy army to shut down due to the original Leroy's fail-safe. Yaarp joins them for the song by playing the built-in horn on his head.

Trivia

 * Yaarp is one of the ten known experiments named by someone other than Lilo, the other nine being Gigi, Elastico, Hammerface, Thresher, Heat, Plasmoid, Morpholomew, Shrink, and Leroy.
 * He is also one of the six known experiments to be rehabilitated by someone other than Lilo and Stitch, the other five being Gigi, Elastico, Spike, Frenchfry, and Snooty.
 * Yaarp was named after a word from Pleakley's home planet.
 * Yaarp is capable of controlling the intensity of his sonic blasts, depending on how he feels around others.
 * In "Spike", only Spike, Fibber, Nosy, Bonnie, Clyde, Slushy and Splodyhead were at Pleakley's E.A.R.W.A.X. group, but in one scene, you can clearly see Yaarp hiding under the couch.
 * Yaarp's pod color is yellow.
 * Yaarp is described by the experiment computer screen as, "Experiment 613 Primary function: Noisemaker."
 * Yaarp's torso and tail appear in the online game Jumba's Lab.