Gantu is the second-in-command to Doctor Hamsterviel, and is the main antagonist of Lilo and Stitch alongside Galaxhar and Fagin.
Gantu appeared at Jumba's trail. Once Gantu observes Jumba's creation he sentences him to prison while the Grand Council Women commanded Gantu to imprison Stitch. Gantu a makes sure Stitch is locked up completely and leaves the room. During Gantu's absence Stitch escapes. Gantu tries to capture him during the escape but was unlucky. The Grand Council women then sends Stitch's creator Dr. Jumba and earth expert Pleakely to capture Stitch. The duo soon fail and The Grand Council Women sends Gantu out to capture the creation. Gantu kidnapps Stitch along with who new friend Lilo. Stitch manages to escape although Gantu is clueless to his escape. Lilo's sister Nani, Stitch and reformed Jumba and Pleakley set off to save Lilo. A battle follows and Stitch save the day. After the battle the heroes and Gantu return to the island. Gantu is then fired from his job.
Gantu didn't appear in Lilo and Stitch 2: Stitch Has a Glitch, but he reappears as a secondary villain ading the evil Dr. Hamsterveil in his goal to take over the galaxy. In this film Gantu kidnaps Jumba and uses him as a hostage in order to gain the the other 624 experiments Jumba created.
Gantu appears as one of the series main villains and is featured in almost every episode. Gantu is now the official henchman of Hamsterveil and plans to capture all 625 experiments. Gantu is given a sidekick as well, the wisecracking experiment number 625.
Gantu reappears once again in Leroy and Stitch. Gantu finally frees Hamsterveil from his prison and useses Jumba's newest experiment Leroy to take over the galaxy. Once Hamsterveil's plans prevails, Gantu is fired from his job. Gantu decides to finally join the heroes and help Lilo and Stitch save the galaxy. Gantu is reformed and finally gets his job as Captain once again and joins Lilo's family or Ohana.
Role in the Series
Gantu was recruited to the Villain League due to Galaxhar's dark side powder on an ambush mission. he'll pretty much rephrease what is mentioned above.
Of course, there's more to Gantu than meets the eye. As it turns out, he is actually a hero nowadays thanks to his partnership with Benny, Leo, and Johnny. Not only that, but he actually has some knowledge of what happened 10 years ago during the events of Birth By Sleep that Hamsterviel needs for Mirage's plans. In fact, Gantu, even before he turned fully evil, was already an antagonist as he fought against Terra, Ven, Aqua, and Tyro on their journey to find Master Xehanort and stop the Unversed.