Shortstuff

Shortstuff, A.K.A. Experiment 297, is an illegal genetic experiment created by Jumba Jookiba. He is designed to sabotage mechanical devices. Due to his accidental enlargement, his one true place is as an amusement park ride. Shortstuff is voiced by Nancy Cartwright.

Personality
Shortstuff is ill-tempered, reckless and clever. Armed with four claws and a very short temper, he's not exactly afraid to take on bigger opponents and is very touchy about his size, after being accidentally enlarged.

Lilo & Stitch: The Series
Experiment 297 was the 297th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to enter machinery and sabotage it from within using his claws. 297 and the other first 625 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 297's pod landing in a sewage pipe.

Stitch was too short to participate in any of the carnival rides, so Lilo treated him to some lemonade instead. However, when the vendor insulted Stitch's size, the latter broke the vendor's lemonade cart. When lemonade from the broken lemonade cart trickled into the pipe, it touched 297's pod, activating the experiment.

Gantu, who was at the amusement park with Experiment 625, went and grabbed 297, but the latter was able to escape by pinching Gantu.

While 297 most likely began his rampage, Stitch, who wanted to be bigger than his normal size, got Lilo to convince Pleakley to enlarge him with Jumba's growth ray.

Unfortunately, during Stitch's growth process, Gantu came to the Pelekais' house looking for 297, which Lilo lied about capturing. Gantu then saw a humongous Stitch towering over him, which was from the growth ray's effects. When Lilo explained what happened and threatened to make Stitch even bigger, Gantu was forced to retreat.

Later, 297 had proceeded to sabotage every ride at the amusement park. He then popped out of a ride control panel before being captured by Lilo and Stitch, the latter having great difficulty due to his enormous size. 297 was then taken back to the house, where Lilo named him Shortstuff.

Unfortunately, Shortstuff was able to use his claws to escape containment, and attempted to sabotage Jumba's growth ray. However, in the process, the ray enlarged Shortstuff into a giant behemoth as he escaped outside. Stitch then requested to be enlarged into an equal behemoth so he could take on Shortstuff.

Meanwhile, Shortstuff resumed his rampage at the carnival, causing panic among the tourists, then faced off against the gigantic Stitch. At first, Shortstuff was able to easily overpower Stitch, but after the latter was shrunk back to his normal, functional size with Jumba's shrink ray, Stitch easily defeated Shortstuff.

Shortstuff's size was never reverted, and as a result, he found a one true place as an amusement park ride.

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

Shortstuff participated in the following battle between the experiments and the Leroy clones by swatting Leroys with his huge claws.

However, 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
Shortstuff made an appearance in the Stitch! anime where Hämsterviel was going to unleash him on the island, but sent Wishy-Washy instead by accident. He was also returned to his normal size in this episode.

Trivia

 * Shortstuff's pod color is green.
 * Shortstuff is described by the experiment computer screen as, "Experiment 297 Primary function: Sabotage mechanical and electrical devices."
 * Oddly, when Shortstuff's image is reflected off of Stitch's eyes in The Origin of Stitch, he is facing directly at the screen instead of to his right.