Experiment 625 was the 625th genetic experiment created by Jumba with Hämsterviel's funding. He was designed for Stitch's purpose (mischief and mass destruction), but was considered a failed experiment due to his lazy nature.
625 and the previous 624 experiments were deactivated and smuggled to Earth by Jumba during his mission to capture Experiment 626.
Before Stitch's creation and when Jumba was struggling with creating his ultimate monster, Reuben served as Jumba's primary assistant in the labs, though this mostly involved him making sandwiches for his master. When Stitch first gets loose on Turo, Reuben comes with Jumba to help him track the creature down, but eventually, the arrest would come and Reuben would be podded.
Reuben appears in the same blue color as Stitch in the prequel comics. This blue color was still kept in the early comics based on the show, persisting even in reprints.
Despite having all the powers of Stitch, Reuben is incredibly lazy. However, during the events of Leroy & Stitch, Reuben finally made something of himself. He is actually very friendly, though he often makes wisecracks, but is usually quite crabby toward others when they disturb him (especially Gantu). He constantly insults Gantu's bumbling nature but secretly sees him as his best friend. He can be considered somewhat of a coward, especially when Gantu forces him to battle Stitch on occasions. Unlike Gantu, however, he shows no fear of Dr. Hämsterviel who apparently resents Reuben because of his laziness. He also has a rather odd love for sandwiches. Most of the time, he is seen with either a finished sandwich in his hand or making one. His sandwiches are apparently very tasty as even Gantu asks for some.
Aside from this, Reuben is incredibly intelligent, especially when it comes to dealing with the experiments. Although he was the second to last experiment to be created, Reuben has excessive knowledge of every experiment, even the ones created far before his time. There are also a few instances where Reuben acts like kind of an "inside man" for Lilo and Stitch, like telling Lilo how to beat Experiment 627.
In Lilo and Stitch (series)Edit
Stitch! The MovieEdit
While Jumba and Pleakley were fighting over the experiment pod container, unseen to them, 625's experiment pod slipped out.
Gantu later discovered the pod while abducting Jumba and took it with him back to Hämsterviel's ship.
When Jumba refused to reveal the location of the other experiment pods, Gantu and Hämsterviel, unaware of 625's lazy nature, decided to activate Experiment 625 and use him to torture Jumba. However, Gantu and Hämsterviel were awestruck to discover 625's lazy nature.
625 later frequently attempted to gain new bologna for his sandwiches, until he was trapped on Earth after Gantu's ship crashed with Gantu and 625 on board.
Lilo & Stitch: The SeriesEdit
Reuben (known as 625 at the time) is still stranded along with Gantu. 625 turns out to be quite intelligent and gives plenty of information about the experiments to Gantu. In the series, 625 was once commanded by Gantu to battle Stitch, but due to his lazy nature, did not fight and was easily beaten. Ironically, he used his powers twice in the series when he climbed up the spaceship window and kicked Gantu along the beach. He is portrayed as Gantu's wise-cracking sidekick and often tags along during experiment hunting. In the episode "Mr. Stenchy", 625 was actually jealous of Gantu's affections towards the newfound experiment Mr. Stenchy.
Throughout the series, 625 served as Gantu's reluctant sidekick, although he usually is no help, messes up Gantu's plans, or even helps Lilo and Stitch against Gantu on some occasions.
Leroy & StitchEdit
With Gantu having failed to capture any experiments other than 625 himself, the former abandoned 625 on Earth and left to free Hämsterviel from prison.
Hurt and/or infuriated at this, 625 decided to convert Gantu's deserted ship into his own sandwich shop.
Sometime later, Lilo visited 625 to use the ship's videophone, and even made him a PBJ sandwich as a peace offering. 625 initially denied Lilo's request until Lilo discovered that she'd never named him (he was still 625 to this point). After a few failed attempts, they finally agreed to Reuben. Lilo then convinced Reuben to repair the ship's communication system so that she could contact Stitch.
After the call was placed, the two discovered that the Stitch in control of the BRB was an imposter. When Lilo asked Reuben for help in saving Stitch, the latter claimed it was not their problem. Lilo then enlightened Reuben on how he could do whatever Stitch can, and convinced him to finally make something of himself. Reuben then repaired the ship, while revealing his incredible powers, and the two flew it to Turo to warn the Grand Councilwoman.
However, as Lilo and Reuben arrived, they discovered that they were too late, and Hämsterviel and his Leroy army had already overthrown the Galactic Alliance.
Hämsterviel ordered Gantu to arrest Lilo and Reuben, but Gantu was fired in the process. However, the two were soon broken out by a reformed Gantu, after Reuben convinced him to switch sides.
Before the three were able to escape, they were recaptured by a group of Leroy guards. However, they were saved by Stitch, Jumba and Pleakley's timely arrival and escaped back to Earth in time to save the captured experiments.
Reuben participated in the following battle between the experiments and the Leroy clones by slipping up Leroys with sandwiches.
When the Leroys gained the upper hand in the battle, Lilo, Stitch, Reuben and several other experiments performed the song "Aloha `Oe", which caused the entire Leroy army to shut down due to the original's fail-safe. Reuben joins them for the song by playing the saxophone.
Following the battle, when the Galactic Alliance was reinstated and Gantu returned to his job as captain, the latter hired Reuben as his galley officer.
After the events of Leroy & Stitch, Gantu was fired as captain (dishonorably discharged) once again and leaves to rejoin Hämsterviel with Reuben tagging along. During the series, he isn't much of an enemy to Stitch even visiting him sometimes. During "Onigiri Reuben," he becomes fond of Japanese riceballs. In spite of his neutrality, Reuben tags along with Gantu and Hämsterviel during the many villainous plots, although he has stated that he doesn't really care who wins. In one episode, Reuben was used in a plot to capture Angel. However, an impressive battle with Stitch ends with Reuben falling into a food stand, having him remember what his real goal in life is—to make and eat sandwiches.
On Sora's TeamEdit
Reuben asked for a job at making delicious sandwiches for all the crew members for the road on each missions as he got recruited on the team.