Fibber

Fibber, A.K.A. Experiment 032, is an illegal genetic experiment created by Jumba Jookiba. He is designed to buzz whenever he hears a lie. He was captured by Gantu, but was rescued in "Snafu". His one true place is at court interrogating suspects with the Kauai police force.

Personality
Fibber appears to be mute (except when buzzing at a lie) and sometimes blank, though he has displayed emotion on few occasions. In "Spike", when Pleakley convinced the other experiments in his E.A.R.W.A.X. group to attempt hugging therapy on each other, Fibber can actually be seen shedding tears.

Lilo & Stitch: The Series
Experiment 032 was the 32nd genetic experiment created by Jumba with Hämsterviel's funding. He was designed to use his lie-detecting ability to force entire civilizations to only ever tell the truth. Based on Jumba's incorrect theory, this would result in a societal collapse. 032 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.

At an unknown point after this, Experiment 032 was activated.

An estimated 12 hours after his activation, 032 was captured by Lilo and Stitch and taken back to the house, where he revealed his powers by buzzing loudly when Lilo lied to Nani about cleaning her room.

On the day after Lilo and Stitch had brought home 032, named Fibber, Pleakley received a call from his mother. She had been badgering her son about finding a wife, and even revealed to the latter that she'd found a perfect bride on Plorgonar and set up an arranged marriage.

Pleakley felt heartbroken, knowing he would have to leave his ʻohana forever, until Lilo suggested that Pleakley tell his mother he is already engaged to a woman. Pleakley said he couldn't lie to his own mother, but then Jumba convinced Pleakley that lying would be the best thing for him to do. So Pleakley called his mother and began telling her about his fake proposal, while Fibber kept buzzing.

Shortly after, Pleakley's relatives came to the Pelekai household to personally witness his sham engagement to Nani (who reluctantly posed as Pleakley's fiancée), which led to a tragic wedding. Meanwhile, Lilo and Stitch attempted to hide Fibber in all sorts of places to drown out his frequent buzzing caused by Pleakley lying to his family.

When Gantu returned from a spa weekend and was informed about the experiment, he crashed the phony ceremony to take Fibber, but was foiled by Lilo and Stitch. Pleakley eventually told his family the truth and stated that he was happy with his life and didn't want to get married. He also made amends with his relatives.

However, as Pleakley's family prepared to depart, Gantu appeared in his hovercraft and captured Fibber. Regardless, Lilo decided to let Fibber stay with Gantu for now. Back at Gantu's ship, Fibber buzzed when Gantu lied to Hämsterviel about his whereabouts.

In "Spike", Fibber was one of the experiments in Pleakley's E.A.R.W.A.X. group. He buzzed during the therapy session whenever one of the other experiments lied (mainly Bonnie, when she lied about her being intelligent and falsely accused Clyde for getting them both arrested). When the other experiments later began to cause chaos, Fibber watched nonchalantly while smiling.

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

In "Woops", Fibber was sent back to Gantu after Experiment 600 caused mayhem and nearly blew Hämsterviel's cover by alerting prison guards.

Fibber reappeared in "Snafu", and was freed along with Gantu's other captive experiments by Lilo, Stitch, and several other experiments in a rescue mission.

The Origin of Stitch
Fibber was one of the experiments that was gliding on the screen, but he is 580 instead of 032.

Leroy & Stitch
The first 624 experiments, including Fibber, 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.

Fibber did not participate in the following battle between the experiments and the Leroy clones, instead choosing to retreat with the weaker experiments.

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.

Trivia

 * It is revealed in his episode that Fibber likes cookies.
 * In "Spike", Fibber was at Pleakley's E.A.R.W.A.X. group, but Gantu captured him. Though he could have temporarily escaped somehow, which would qualify him as a truant experiment.
 * It is also possible that the episode chronologically takes place after "Snafu", given that Nosy is also present.
 * In "Snafu", Fibber did not buzz when Reuben said he's not ticklish. It is possible that the containers are soundproof or Fibber just wasn't paying attention. Arguably, Reuben maybe really thought he wasn't ticklish.
 * Fibber's pod color is green.
 * Fibber is described by the experiment computer screen as, "Experiment 032. Primary function: Lie detector."
 * Fibber's head appears in the online game Jumba's Lab.