Morpholomew

 Morpholomew, A.K.A. Experiment 316, is an illegal genetic experiment created by Jumba Jookiba. He is designed to morph organisms into any other organism. His one true place is at a costume store. He is voiced by Frank Welker.

Bio
Experiment 316 was the 316th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to morph organisms into any other organism, after seeing the target organism or a photo of the target organism at least once before. However, someone who has been morphed keeps the same voice and needs 316 to change back.

316 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 316's pod landing on a hay umbrella.

Lilo and Stitch: The Series
At the beginning of the episode, Lilo decides to enter the local skate competition in order to win a brand new skateboard, the Velociraptor 1200, for her crush Keoni, after practicing for a while on her own skateboard.

Before the event, Stitch and her discover Experiment 316, which was activated in a fountain after Stitch pulled Lilo's crashed skateboard from a straw umbrella. Experiment 316 is a creature capable of giving anyone the appearance of someone else. Lilo uses this power in order to enter the competition as Keoni.

In the meantime, Jake, Lao Shi, Fu Dog, Trixie and Spud arrive at the Kauai skate competition. They are looking into the reports of undisguised magical creatures lurking on the islands of Hawaii (actually Jumba's experiments), although Jake is more interested in winning the contest's grand prize. All of them separate to go on their own business: Lao Shi gets enamored by Mrs. Hasagawa, Trixie and Spud head to the beach, Fu Dog goes to place some bets on Jake while the latter signs up for the skateboarding competition. Lilo does the same, but soon realizes that impersonating Keoni was probably a bad idea when she earns a low score. She asks for Experiment 316 to change her into absolutely anybody so she can start over, but registrations close before she gets a chance to sign up again.

Meanwhile, Jake, having spotted Experiment 316 with Lilo and mistaking it for a magical creature, transforms into the American Dragon and gets ready to pursue them. However, Jake is captured by Gantu who mistakes him for Experiment 316. Since Jake doesn't show for the competition, Lilo decides to turn into Jake with Experiment 316's help and enter in his stead.

Meanwhile, Jake escapes Gantu's lair before he is transferred to Hämsterviel's asteroid and heads back to the skate park. However, Lilo has already taken his place and fails once again to score any points. Trixie and Spud grow suspicious of Lilo (still disguised as Jake) while she throws a tantrum when Stitch tells her that Experiment 316 was captured by Gantu. They know something is up when Lilo panics upon hearing Fu Dog speak. The real Jake (in his Dragon form) arrives at that moment, and engages into a fight with Stitch. Before things get too far, Lilo manages to calm everyone down and explain the whole situation.

Once everything is clarified to everyone, they decide to team up and retrieve Experiment 316. They go to Gantu's lair and fight against him to get Experiment 316 back. In the confusion, the team tricks Gantu into thinking he captured Experiment 316, when in reality Spud assumed the little creature's form and got kidnapped instead. Thanks to this, Jake and Lilo manage to get Experiment 316 back and change Gantu into a white little bunny as punishment for all the trouble he caused. The team then heads back to the skateboard competition where the winner claims the Velociraptor 1200. Jake and Lilo are a bit bummed by this, but are happy to have made new friends. They leave on good terms and promise to see each other again soon.

Leroy & Stitch
Morpholomew was seen early in the movie as Lilo was making her rounds with Scrump to make sure all the experiments were happy in the one true place they belonged.

The first 624 experiments, including Morpholomew, were round 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.

It is unknown whether or not Morpholomew 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 failsafe.

Stitch! anime
Morpholomew fell under Hämsterviel's possession under unknown circumstances. He was modified to morph his own body instead of others, and was given a vocabulary.

At an unknown time after this, Lilo, now an adult, took a vacation with her daughter, Kidda, to an island in Japan, where, unbeknownst to them, Stitch was at the time. Kidda met Stitch, who mistook her for a de-aged Lilo, and they played together.

Hämsterviel took advantage of this and sent Gantu to use Morpholomew to take the image of her and distract Stitch long enough to capture him.

Personality
Morpholomew is very curious, as he chased a noise which he found to be a rabbit. He is one of the few experiments that demand payment, which he considers to be chicken legs. He loves chicken legs so much he can go through dozens of buckets of them in only a few minutes.

Trivia

 * Morpholomew is one of the ten known experiments named by someone other than Lilo, the other nine being Yaarp, Gigi, Elastico, Hammerface, Heat, Thresher, Plasmoid, Shrink, and Leroy.
 * When the American Dragon cast first encounters Stitch, they all think he's a messed up Leprechaun.
 * While Lao Shi and Mrs. Hasagawa are on their date, they do stereotypical activities often associated with new couples: long walks on the beach, romantic dinner, and even a show-off of skills from Lao Shi.
 * It is revealed that Spud is afraid of sharks, although he gets over his fear at the end of the episode.
 * Spud is the one that finds Experiment 316's new name, Morpholomew.
 * When Jake Long was in his dragon form, he was mistaken for Morpholomew by Gantu.
 * In this episode, Jake's dragon form's mane and spikes flutter in the wind when airborne, which is not the case in the actual American Dragon show.
 * The entire American Dragon cast is drawn in its Season 1 design.
 * This is the only crossover episode of American Dragon: Jake Long, but is the first of four for Lilo & Stitch: The Series.
 * When this episode aired for the first time on The Disney Channel, a new episode of American Dragon: Jake Long was also aired the same day ("The Long Weekend" of Season 1).
 * According to the broadcast information of the series, this episode is meant to take place after the episode "Body Guard Duty" of Season 1.
 * In this episode, the scene where Lao Shi and Mrs. Hasagawa eat spaghetti at a Hawaiian restaurant is a reference to a very similar scene featured in the Disney movie Lady and the Tramp.
 * The same scene is also parodied later in Phineas and Ferb and Gravity Falls, in the episodes "Phineas and Ferb Summer Belongs to You!" (by Buford Van Stomm and Baljeet Tjinder) and "The Time Traveler's Pig" (by Mabel Pines and Waddles eating a slice of pizza together), in order.
 * Morpholomew's pod color is yellow.
 * Morpholomew is described by the experiment computer screen as, "Experiment 316 Primary function: Shapeshifter."
 * Morpholomew is one of the few experiments to not appear in the group photo at the end of Leroy & Stitch.