Dr. Jacques von Hämsterviel is the main antagonist of the Lilo & Stitch franchise. His first appearance was in the 2003 film Stitch! The Movie, where he begins plotting to take over the galaxy. He is the former partner of Jumba Jookiba, who later becomes one of his main enemies.
Before the events of the franchise, Hämsterviel worked alongside Jumba Jookiba as a scientist. Together, they made genetic illegal experiments. According to Jumba, it was Hämsterviel that went to the authorities about the illegal experimentation. Hämsterviel was more than likely arrested as well because of the heavy affiliation. Apparently, Hämsterviel's plan was to: fund Jumba's experiments, then take them for himself, then squeal on Jumba and take over the universe.
Little did Hämsterviel know, Jumba was released to capture his latest experiment 626. During these events, Jumba reformed and spent his days on Earth with a new family. Eventually, Hämsterviel would escape, recruits the former captain of the Galactic Federation as his henchman, and seek to regain "his" experiments. Hämsterviel's attempts failed but the constant failures did not prevent the mad scientist from trying again. Years after these events, Hämsterviel sets out to harvest absolute power instead.
Hämsterviel seems to have a bit of a Napoleon-complex as, despite his short stature, he has a large, imposing character and wants nothing less than total galactic domination, as he is extremely self-absorbed, viewing no one (not even his former partner Jumba or his henchman Gantu) as his equal. He insults everyone he sees, even when they do something for him or have not done anything at all. Not to mention, he often acts like a spoiled brat, throwing a tantrum when he does not get his way, and will take his frustration out on anyone.
He is cunning, diabolical, and very abusive to his henchman Gantu, whom he frequently assaults with a plethora of poorly-formed, albeit demeaning and redundant insults (which could hardly even be called insults) for his failures to capture the experiments; even when Gantu manages to capture a few experiments, Hämsterviel never thanks him for it. He also does not care about his minions, so long as they outlive their usefulness to him. However, despite Gantu's loyalty, as well as helping him escape jail in Leroy & Stitch, after Hämsterviel's objectives had been achieved, saying that since he had Leroy to do a better job, Gantu was of no use to him anymore. This horrible treatment was one of the things that proved to be his downfall, as Gantu would later help Lilo and Stitch into defeating Hämsterviel out of spite against him.
Hämsterviel also hates his old business partner Jumba, as well as Stitch, Lilo, Pleakley, and later Yuna. His schemes have sometimes been directed at them, either to enslave them or even kill them. Originally, he schemed to capture the 625 experiments that Jumba created before Stitch and use them in his bid to conquer the galaxy, viewing them as his own property because he financed their creation using his shady business deals.
Hämsterviel (or a reasonable facsimile) had a small non-speaking cameo around the start of the film when Pleakley and the Grand Councilwoman make way for Jumba's jail cell. However, this was a mere background appearance with no significance whatsoever.
Hämsterviel appears as the main antagonist of the film, setting up his role for the rest of the franchise. Here, with his new associate Gantu, Hämsterviel plots to take over the galaxy by using the power of Jumba's 625 experiments who have been podded since Jumba's arrest. He orders Gantu to find the pods, which are located in Jumba's room in Hawaii. Once the experiments are captured, Lilo and Stitch head over to Gantu's ship before the plan can be complete. Lilo is captured as well as Stitch. While Lilo is put into a cell, Hämsterviel plots to cut Stitch in half via a laser. However, Stitch breaks free and traps Hämsterviel onto the platform. After Lilo's rescue and a scuffle with Gantu, the experiments are accidentally released on Hawaii. With Hämsterviel under arrest, Lilo and Stitch prepare a hunt for each experiment with the exception of 625, whom Hämsterviel unleashed thinking he would be another Stitch power wise, but instead, he was a lazy sandwich maker.
Hämsterviel currently resides at the Galactic Prison, where in his cell, he communicates with his minion, Gantu. He constantly appears on a giant screen in Gantu's home, giving him orders and constantly berating and scolding him about his endless line of failures. On occasion, he has escaped prison and went to Earth. In one episode, he accidentally became the pet of Lilo's rival, Mertle. Eventually, he has grown to like her and is currently her only friend.
In Leroy & Stitch, Hämsterviel escapes from prison with the help of Gantu, and forces Jumba to create a new experiment, which the alien rodent names Leroy. He then repeatedly clones Leroy and uses the clones to take over the Galactic Alliance, firing Gantu afterwards for his incompetence. This proves to be the key to his downfall, as Gantu breaks Lilo and 625 out of prison. When Hämsterviel goes to watch Leroy and his clones destroy the other experiments, his plan is thwarted by the arrival of the reformed Gantu, Lilo, Stitch, Reuben, Jumba, and Pleakley, who team up with all the other experiments and defeat Leroy. After Lilo, Stitch and Reuben defeat all of the Leroy's with "Aloha `Oe", the remaining angry experiments toss him around like a beach ball, causing him to yell, "I am not beach ball light. I am hamster light!" Hämsterviel is sent back to prison afterward, with all the Leroys in the cells around him.
In the anime series, Hämsterviel, appearing as the main antagonist in the first and second season, plots against Yuna and Stitch alongside his lackeys Gantu and 625. Unlike the previous series, Hämsterviel frequently goes out into the open to take control over Stitch. In this show, Hämsterviel plots to become the most powerful being in the universe, thus giving him the advantage of taking over the galaxy with ease. In one special episode entitled "Stitch Vs. Hämsterviel", his goal is completed but ended after an epic battle with Stitch. A running gag in the series includes several characters mistaking Hämsterviel for a rat-like creature as opposed to a hamster-like. This gag echoes the previous misconception of Hämsterviel being a gerbil-like creature. He appears as the secondary antagonist in the third season.
Dr. Hämsterviel appears as a walkaround at Tokyo Disneyland along with many other characters from the franchise, as the film and television series are some of the most popular Disney media in Japan. Hämsterviel also made an appearance in Disneyland Paris as part of Stitch's Hawaiian Paradise. Hämsterviel is also seen atop a float in the parade Lilo and Stitch's Big Panic: Find Stitch.
At Tokyo Disneyland, Hämsterviel plots to finally capture Stitch and steal his powers. When his minions locate him, they travel to Earth to make the move. Hämsterviel sends Gantu to proceed with the capture, but the bumbling captain fails and joins Lilo and Stitch's party instead. After all seems lost for the villains, Hämsterviel arrives but decides to join as well with no minions to assists him with the plans.
In the Polish translations of the Lilo & Stitch media, his name changes from Chomikviel (meaning literally "Hämsterviel") to Chomikvader (Hämstervader), which is an obvious reference to Darth Vader. Hämsterviel is, however, referred to as Chomikviel in The Series only, and as Chomikvader in a majority of other media.
He is perhaps the most significant villain related to the Disney animated canon to not feature in the original film of his property and only appear in sequel media.
In the first film, a Hämsterviel look-alike can be seen in one of the prison cells on Asteroid K-37.
Hämsterviel is an expert laser-sword duelist.
Hämsterviel's phone number is: 555-019-829-3434-533-65-5882.
His prison in Xenon Sector: Prison Asteroid K-37 is Cell 750.
Hämsterviel is a play on the term "hamster wheel", an exercise decoration commonly placed inside most hamster enclosures. This is actually a running gag throughout the franchise.
It is unknown if Hämsterviel's accent is supposed to be either French or German, since "Jacques" is obviously French (the equivalent of "John"), and "Hämsterviel" is clearly German-sounding with an accent over the "a" in his last name.
Many other characters mistake him for a gerbil-like creature or a rat-like creature, though he insists that he is hamster-like. However, despite this, and the fact that he has the word "hamster" in his name, Hämsterviel actually looks more like a rabbit than a gerbil or hamster.
He also resembles a rabbit with albinism due to his bright red eyes and almost complete lack of pigmentation in his fur, though it is unknown if he suffers from the condition himself.
After the events of Leroy & Stitch, Hämsterviel was freed by Gantu. It was also revealed in the Stitch! anime that Hämsterviel partnered with Delia whom he and Jumba met long ago in "Stitch's Birthday: Part 1".