Mr. Stenchy

Mr. Stenchy, A.K.A. Experiment 254, is an illegal genetic experiment created by Jumba Jookiba. He is designed to use his charm to get the enemy to take him to their headquarters, where, 42 hours after his activation, he emits a noxious odor that makes the location inhospitable. His one true place is on Plorgonar (Pleakley's home planet), where his stench is considered a rare and valuable perfume. Mr. Stenchy is voiced by Frank Welker.

Personality
Due to his disarming cuteness, Mr. Stenchy gains much attention from humans, but not so much from other experiments. He also appears to act as cute as he looks.

Lilo & Stitch: The Series
Experiment 254 was the 254th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to use his cuteness to smitten Jumba's enemies into taking him back to their headquarters, where 254 would emit a noxious odor that would make 40 square miles of the area uninhabitable for decades. 254 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 254 was activated.

An estimated 12 hours after his activation, 254 was captured by Lilo and Stitch and taken back to the house, but not before being pursued by Gantu.

Lilo had fallen for 254's cuteness and decided to keep the newly-christened Mr. Stenchy, despite Jumba's warnings about him serving as a ticking stink bomb. Stitch, however, got jealous of Mr. Stenchy and was immune to the latter's charm. He even relentlessly bullied and tormented Mr. Stenchy.

Later, Lilo began taking Mr. Stenchy to Mertle's tea parties in an attempt for the former to be accepted into their group. Of course, Mertle and the hula girls fell for Mr. Stenchy's charm ever since Lilo first introduced him to them.

When Stitch was left home alone with Mr. Stenchy, the latter made several vain attempts to get Stitch to like him. However, Stitch ended up locking Mr. Stenchy in the pantry. Gantu later attacked the house, but Stitch (having two shoulder devils) allowed Gantu to take Mr. Stenchy so that the former would be rid of them both.

However, back at Gantu's ship, Gantu also fell for Mr. Stenchy's charm before he could teleport the latter to Hämsterviel. This made Experiment 625 envious like Stitch, though Gantu took little notice and kept pampering Mr. Stenchy.

Thus, Gantu began to grow attached to Mr. Stenchy until Lilo and Stitch arrived later to take him back. Due to Stitch abandoning him, Mr. Stenchy chose Gantu. However, Mr. Stenchy then began to emit his stink, forcing Gantu to hand the former over. Although Mr. Stenchy reeked, it didn't faze Pleakley at all.

Mr. Stenchy was then sent to Plorgonar in a rocket, where he could be loved in spite of his smell, as it was considered appealing on Pleakley's home planet.

Leroy & Stitch
Mr. Stenchy inexplicably reappeared back on Earth and not producing his deadly stink, suggesting it wears off after a while.

Later, the first 624 experiments, including Mr. Stenchy, 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.

Mr. Stenchy participated in the following battle between the experiments and the Leroy clones, as in one scene, Mr. Stenchy can be seen around some of the Leroys.

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.

Stitch! anime
Mr. Stenchy appeared twice in the Stitch! anime. He first premiered when he fell in love with Stank, and again later on when Hämsterviel made several clones of him and Mrs. Sickly as Christmas toys. It is revealed that when his stench is combined with Mrs. Sickly's, it could cause an explosion that has the power to destroy a planet.

Trivia

 * Stitch and Reuben were unmoved by Mr. Stenchy's cuteness, as Jumba pointed out that other experiments are immune to Mr. Stenchy's charm.
 * In Leroy & Stitch, Mr. Stenchy inexplicably returned to Earth from Plorgonar. Also, he did not produce his stink, suggesting it wears off after a while or he has learned how to control it.
 * Mr. Stenchy's pod color is green.
 * Mr. Stenchy is described by the experiment computer screen as, "Experiment 254 Primary function: Stink bomb. Emits a noxious odor that makes the location inhospitable."
 * In the Stitch! anime, Mr. Stenchy has a wife named Mrs. Sickly.
 * Mr. Stenchy's head, antennae and ears appear in the game Jumba's Lab.